I have seen a huge number of kdramas over the years, and as you know, I am obsessed with lists. I have calculated, and there are over 70 kdramas where I have seen enough to have a decided opinion about quality and rankings. Now, if I've seen all of a kdrama, of course it's ranked. But if I have only seen part, it will depend on a kdrama. E.g., I've seen more eps of Jumong than some dramas even have, but you won't find it on this list because it's such a long drama and with such a complex story arc, that I don't feel like I can rate it until I am at least up to ep 40. OTOH, with some dramas it only takes an episode. Nobody said I wasn't judgmental.
I am going to split these posts into 7 parts, with ten or so dramas per post, going backwards.
Below, are dramas from the very bottom of the barrel. Most of them elicit this reaction in me:

Anyway, presenting, in backwards order, Dangermousie's list of love and snark.
(76) FLY HIGH
I freely admit I have only seen two episodes of this drama, and for all I know, it can turn into a masterpiece by ep 3. However, I doubt it, seeing that the actors are wooden and chemistry-less, the writing mediocre at most, cinematography is horrid, and it's sprinkled with Engrish. The story? A plucky almost-widow of comatose guy from an aristocratic but improverished family and an 'adopted by Americans' icy CEO fall in love. You think you can't miss with that story but you'd be wrong. I have never heard of these actors before and hope never to again but, to be fair, they have little to work with. It's the kind of drama that drearily marches through the paces while making me roll my eyes, e.g. (1) its cute 'clumsy' heroine, even if a single mother, acts like a braindead 12-year-old, with her "adorable" clumsiness, and (2) the hero's hidden angst never comes across in either acting or things he is forced to say.
(75) LOVE STORY AT HARVARD
I got through 6 eps of this and I deserve a medal. Kim Rae Won is one of my favorite actors, but the dramas he picks - my God! This was a hit but the story of twwwwwwuuu luv between two Koreans studying at Harvard - he a wannabe lawyer from a rich family, she a poor wannabe doctor - just didn't work for me at all. I think I was about the wrongest audience possible - incessant horrific Engrish and bizarre take on America really dragged me out of it all (they bond over bathing an AIDS victim!) Plus, it was just so dull...
(74) TAMRA THE ISLAND
There is a way to do an anachronistic drama right, using anachronism as clever highlights. And then there is this albino-starring, potty-humored, overacting mess of a drama about an Englishman washed on Jeju Island back way when, a diver girl (dumb as rocks) and a young aristocrat in exile. Ugh. Even the fight scenes look anemic.
I watched more and had to eat every word. Replaced by Super Rookie in this spot.
(73) CINDERELLA MAN
Kwon Sang Woo makes me think of Kim Rae Won - I love the guy but what goes through his head while picking dramas, is a mystery known to God alone. Here he plays twins, acts much younger than his age (and the age he looks), has a teenage love interest in Yoona, surely worst actress to ever grace the Korean screen, and otherwise commits a sin against humanity in this pointless tale of the fashion world.
(72) THE KING AND I
I only saw two eps and that was enough - why anybody thought a 60+ ep drama about a eunuch, involving an interminable number of deadly-dull characters whose relationships to each other are murky, was a good idea, I do not know. Apparently they were right and it was a hit, proving once again that what I want to see and what an average Korean wants to see, isn't the same thing. Though it was the only drama where I saw a murder by bees, so I did learn something new. A pity the bees didn't eat the script.
(71) ONLY YOU
Proof positive that Delightful Girl Chunhyang was a fluke and Han Chae Young is as wooden as she is gorgeous. This story about a one-night stand that turns into a baby tries to be so many things, including Memories of Bali copycat. Alas, the story is as dull as the dishwater in the restaurant HCY works, and she and her co-star Jo Hyun Jae (who looks and acts like a particularly dull middle manager) have no chemistry.
(70) MY LOVE PATZZI
The only good thing about this dull, indecisive drama starring the dull Jang Nara, is that it's 10 episodes long. For God's sake, they set this in an amusement park, and it was still dull.
(69) HEADING TO THE GROUND
Soccer. Pop idol in his first starring role. Go Ara who is very cute. Mix it all up and get this shockingly 'meh' drama - haphazardly put together, acted with all the skill of a group of community theater understudies and a definite miss.
(68) MY NAME IS KIM SAM SOON
I have ranted enough about this drama elsewhere but suffice it to say that the enduring popularity of this I will never get. The hero is immature, the heroine is a cheater with no self-esteem, everyone around is largely unpleasant and over-the-top. Ugh.
(67) HANOI BRIDE
A quick, two-episode special about a Korean doctor and a half-Vietnamese girl he falls in love with and loses, until she shows up engaged to his older brother, there is nothing wrong with this drama - the stars do a good job with what they are given, but the problem is it's not much. It's such a trifle that it's hard to remember what it was about two minutes after it ended.
(66) LEGEND OF HYANG DAN
This quick drama (also two eps) takes the famous legend of Chunhyang and turns it on its head, positing that Mongryong was in love with Chunhyang's servant instead. The problem is, it has all been done elsewhere and better - the movie Chunhyang was a gorgeous telling of the traditional tale, Delightful Girl Chunhyang is a sharp transplantation to the modern world, and Hong Gil Dong is an anachronistic, populist rebel drama that has emotionally and intellectually arresting things to say. LoHD just makes me compare it with those and it falls far short.
(65) FANTASY COUPLE
The only Hong Sisters drama I do not adore, I simply could not get interested in this drama take on the famous 1980s movie Overboard, about a rich bitch who loses her memory and is turned into a housewife. I couldn't click with the characters, the plot, anything. I fastforwarded faster and faster and only finished it out of sheer stubborness and because I was on a train. Perhaps it should have stayed a movie.
Coming next time: dramas ranked 64 - 53 - not masterpieces, but enjoyable enough.
As I'll get closer and closer to dramas I love, I'll start providing caps and vids :)
I am going to split these posts into 7 parts, with ten or so dramas per post, going backwards.
Below, are dramas from the very bottom of the barrel. Most of them elicit this reaction in me:

Anyway, presenting, in backwards order, Dangermousie's list of love and snark.
(76) FLY HIGH
I freely admit I have only seen two episodes of this drama, and for all I know, it can turn into a masterpiece by ep 3. However, I doubt it, seeing that the actors are wooden and chemistry-less, the writing mediocre at most, cinematography is horrid, and it's sprinkled with Engrish. The story? A plucky almost-widow of comatose guy from an aristocratic but improverished family and an 'adopted by Americans' icy CEO fall in love. You think you can't miss with that story but you'd be wrong. I have never heard of these actors before and hope never to again but, to be fair, they have little to work with. It's the kind of drama that drearily marches through the paces while making me roll my eyes, e.g. (1) its cute 'clumsy' heroine, even if a single mother, acts like a braindead 12-year-old, with her "adorable" clumsiness, and (2) the hero's hidden angst never comes across in either acting or things he is forced to say.
(75) LOVE STORY AT HARVARD
I got through 6 eps of this and I deserve a medal. Kim Rae Won is one of my favorite actors, but the dramas he picks - my God! This was a hit but the story of twwwwwwuuu luv between two Koreans studying at Harvard - he a wannabe lawyer from a rich family, she a poor wannabe doctor - just didn't work for me at all. I think I was about the wrongest audience possible - incessant horrific Engrish and bizarre take on America really dragged me out of it all (they bond over bathing an AIDS victim!) Plus, it was just so dull...
There is a way to do an anachronistic drama right, using anachronism as clever highlights. And then there is this albino-starring, potty-humored, overacting mess of a drama about an Englishman washed on Jeju Island back way when, a diver girl (dumb as rocks) and a young aristocrat in exile. Ugh. Even the fight scenes look anemic.
I watched more and had to eat every word. Replaced by Super Rookie in this spot.
(73) CINDERELLA MAN
Kwon Sang Woo makes me think of Kim Rae Won - I love the guy but what goes through his head while picking dramas, is a mystery known to God alone. Here he plays twins, acts much younger than his age (and the age he looks), has a teenage love interest in Yoona, surely worst actress to ever grace the Korean screen, and otherwise commits a sin against humanity in this pointless tale of the fashion world.
(72) THE KING AND I
I only saw two eps and that was enough - why anybody thought a 60+ ep drama about a eunuch, involving an interminable number of deadly-dull characters whose relationships to each other are murky, was a good idea, I do not know. Apparently they were right and it was a hit, proving once again that what I want to see and what an average Korean wants to see, isn't the same thing. Though it was the only drama where I saw a murder by bees, so I did learn something new. A pity the bees didn't eat the script.
(71) ONLY YOU
Proof positive that Delightful Girl Chunhyang was a fluke and Han Chae Young is as wooden as she is gorgeous. This story about a one-night stand that turns into a baby tries to be so many things, including Memories of Bali copycat. Alas, the story is as dull as the dishwater in the restaurant HCY works, and she and her co-star Jo Hyun Jae (who looks and acts like a particularly dull middle manager) have no chemistry.
(70) MY LOVE PATZZI
The only good thing about this dull, indecisive drama starring the dull Jang Nara, is that it's 10 episodes long. For God's sake, they set this in an amusement park, and it was still dull.
(69) HEADING TO THE GROUND
Soccer. Pop idol in his first starring role. Go Ara who is very cute. Mix it all up and get this shockingly 'meh' drama - haphazardly put together, acted with all the skill of a group of community theater understudies and a definite miss.
(68) MY NAME IS KIM SAM SOON
I have ranted enough about this drama elsewhere but suffice it to say that the enduring popularity of this I will never get. The hero is immature, the heroine is a cheater with no self-esteem, everyone around is largely unpleasant and over-the-top. Ugh.
(67) HANOI BRIDE
A quick, two-episode special about a Korean doctor and a half-Vietnamese girl he falls in love with and loses, until she shows up engaged to his older brother, there is nothing wrong with this drama - the stars do a good job with what they are given, but the problem is it's not much. It's such a trifle that it's hard to remember what it was about two minutes after it ended.
(66) LEGEND OF HYANG DAN
This quick drama (also two eps) takes the famous legend of Chunhyang and turns it on its head, positing that Mongryong was in love with Chunhyang's servant instead. The problem is, it has all been done elsewhere and better - the movie Chunhyang was a gorgeous telling of the traditional tale, Delightful Girl Chunhyang is a sharp transplantation to the modern world, and Hong Gil Dong is an anachronistic, populist rebel drama that has emotionally and intellectually arresting things to say. LoHD just makes me compare it with those and it falls far short.
(65) FANTASY COUPLE
The only Hong Sisters drama I do not adore, I simply could not get interested in this drama take on the famous 1980s movie Overboard, about a rich bitch who loses her memory and is turned into a housewife. I couldn't click with the characters, the plot, anything. I fastforwarded faster and faster and only finished it out of sheer stubborness and because I was on a train. Perhaps it should have stayed a movie.
Coming next time: dramas ranked 64 - 53 - not masterpieces, but enjoyable enough.
As I'll get closer and closer to dramas I love, I'll start providing caps and vids :)