I am brand new to the k/c/j/x-drama world, mostly I read manga and novels.  I've tried a couple dramas, but I usually abandoned them by episode three until this week when I got hooked on Love O2O.  Thinking about what I liked the most, I realized it was the relationship between the two mains, which is similar to those of my favorite mangas and romance novels, and am seeking guidance on dramas with a similar vibe.   

Any recommendations on dramas (or movies) where the main OTP has some of the following:

1.  They get together as a couple before the half-way mark - I don't care if it's because they fall in love, are in an arranged marriage, etc.  I just like them to be a couple instead of spending 90% of the time angsting about unrequited love.

2. They treat each other with respect -  I abhor any story where the ML treats the FL like something he found on the bottom of his shoe.  I don't mind if they get off on the wrong foot initially (a la Pride and Prejudice) but by the quarter mark I expect them to at least like each other as human beings.  (i.e. Playful Kiss and its imitators is right out!)

3. Character/couple development - I love stories where they grow and change both as individuals and as a couple through their relationship with each other.  (Loved the manga of Kyō, Koi o Hajimemasu for this reason)

4.  Fluff or steam - kissing, flirting, playfulness, or just straight-up chemistry is a must

Please, please help me find some good places to dive into this genre!

Buzzer Beat - They're together for I think 5 of 11 episodes. But amazing chemistry and still some of the best kissing scenes in jdrama land.
Queen Inhyun's Man - Been a while since I watched this one, but I'm pretty sure it fits what you're looking for perfectly.
Nigeru wa Haji da ga Yaku ni Tatsu - Contract marriage - decided by themselves. Quite unusual in the romance department. LOTS of character development.

All of them have very nice male leads, no assholes.


As NanaChin recommended, you should watch Nigeru wa Haji da ga Yaku ni Tatsu. I'm currently watching it; it's quite eccentric and slow-paced. However, watching the characters and romance develop makes this series quite endearing. ^^
Try " Weightlifting fairy Kim Bok Joo" does not fulfill all your requirements ( steamy scenes) but the guy definitely respects the heroine after the first episodes. One of the first J- series I watched was "Tatta Hitotsu no Koi" it's a very sweet love story where the male is poor and the girl is rich and they decided to be together in the middle of episodes .
If you like mature relationship I ll suggest you to look into movies.
" My PS partner " with Ji Sung. its a romantic comedy  worth to watch.
"Mood of the day"
with Moon Chae Won.

Oh My Venus! I can't remember if they get together before the halfway mark but it definitely has all of your other requirements!
My Sunshine. It sounds like a drama cliche, but the relationship is surprisingly mature. Something about 1%. They aren't traditionally together but I think you'll like it.
Boss and Me
Something about 1%
Tomorrow With You (Ongoing drama)
Cheese in the trap
Discovery of romance
Hapimari: Happy Marriage!?
Legend of the Blue Sea
Marry Me, or Not?
The K2
Thanks to everyone who's given a suggestion, tracked down and book marked all of them.  I'm really excited to know there's a live-action 'Happy Marriage' - that is on my short-list of all time favorite manga. Also Boss and Me, Nigeru wa Haji da ga Yaku ni Tatsu, and My PS Partner also look interesting to me.  Tried the first episode of the Nigeru... last night and it seems right up my ally.
Pride
Buzzer Beat
Weighlifting Fairy Kim Bok Joo
Something about 1 Percent
Tatta Hitotsu no koi
We got married as a job
Queen In Hyun's man
Mars (twdrama)
Creating destiny
The greatest love
Thanks everyone whose given me rec's - I have a long watch list now and am very happy.
If you like Akuma de Sourou then there's a drama version, the devil beside me.  Been a while since I watched it but I remember it not being too far off. The manga is a person favorite of mine.  Might try W.  It is kinda plot heavy and romance is sorta a side-plot but they still get together fairly early on and the mutual attraction is obvious....just plot gets in the way for a little while...Haven't finished it though.  
Second Doctors...I'm really enjoying it.  Although there's a side character I really like and I keep getting hung up on him and then look for other dramas with similar characters so I get derailed :D  
I haven't watched "Love O2O" but based on your description, all i can think of is It's Okay That's Love!
It portrays mental issue as the main plot, mature relationship, brilliant chemistry (i can guarantee this one!).
you might wanna check this one out, whether you like it or not: Preview

A new chinese drama called flipped has lots of cuteness and they get together early on. It's still on going though.

Btw I feel you, I also like watching my couple together early on.