I'm looking for dramas where the romance is front and center, and the main couple are nice to each other and supportive of / devoted to each other for the majority of the drama, and preferably where the main characters are not superficial. 

Warning: potentially some minor spoilers ahead when I use examples of what I'm looking for

I love dramas where its obvious that the couple really cares for each other (e.g. Coffee Prince) and worries about one another (e.g. Healer), and its even better if they work really well as a team (e.g. Healer, Princess Wei Young, Bromance) and really trust / support one another (e.g. Love O2O).
I don't mind some clashes or antagonism between the leads in the beginning (in fact I usually prefer it), but only if it's relatively short lived and light-hearted, and not cruel (e.g. Love in the Moonlight, Weightlifting Fairy Kim Bok Joo, SKKS).

If one of the characters is hard on the other because they want to help them and / or because they are hiding their feelings for them (e.g. Go Ho's Starry Night) that's great as long as they're not cruel and preferably if they're actually looking out for that person (GHSN) or just really believe in that person (SKKS). Even if all the other elements are there, I find it really kills the mood for me when one of the romantic leads is unnecessarily mean to the other (e.g. Boss and Me, King2Hearts).

I know there's probably no drama that has all of these things, but please recommend any shows that have some of these elements! Thank you!
The leads in Fight For My Way are very supportive of each other as they're childhood friends. Their feelings towards each other gradually change, so it takes a quite while until we can finally call them a couple, but the drama's pace up to now is just right in my opinion! Their personalities are very likable, too. Both of them are so cute and refreshingly bold!
Strong Woman Do Bong Soon, even though they bickered a lot, it was obvious from the beginning that the male lead really cared for the the female lead, and they had great chemistry...
Queen of Mystery, it didn't have "romance" per say, but the main leads worked greatly together, and  the male lead really respected the female lead, and they made the perfect team while solving crimes ^^
Man I am looking for the exact same thing...but it's very hard, what we want goes against the korean tradition :D I hope someone knows something else from what I have seen.
I would recommend Murphy's Law of Love. The drama primarily focuses on the relationship of the two leads and is mostly fluff between them ~~ Although the main lead is supposed to be cold, he's actually really sweet! Also Refresh Man is another Taiwanese drama that fits your criteria.
High School King of Savvy (2014) 
Faith
Witch's Romance
Bromance
Blood
Doctors
Beautiful Gong Shim
Love Me If You Dare
The New World 
Buzzer Beat

Goblin (he's basically her fairy godmother)
Oh my Venus (kindest and most supportive male lead award goes to So Ji Sub)
Descendants of The Sun (both main and second leads are supportive and caring)
Kill Me Heal Me ( the title says it all)
Reply 1988 (the entire cast has each other's backs)
The Liar and his Lover (2017) has exactly what you are looking for. It's actually like a real life bf/gf romance.

RE: its obvious that the couple really cares for each other (e.g. Coffee Prince) and worries about one another (e.g. Healer), and its even better if they work really well as a team (e.g. Healer, Princess Wei Young, Bromance) and really trust / support one another (e.g. Love O2O).
I don't mind some clashes or antagonism between the leads in the beginning (in fact I usually prefer it), but only if it's relatively short lived and light-hearted, and not cruel (e.g. Love in the Moonlight, Weightlifting Fairy Kim Bok Joo, SKKS).

Also, Boss and Me (Chinese drama) - Male falls first and the female lead is all he sees. He's also supportive of her and doesn't let anyone mistreat her. 

However, both these dramas are pure fluff and the pacing is gentle.
Suspicious Partner for sure!
Smile, you
They always got each other's back and after they started dating they never broke up (even though it's a long drama and they had to hide their relationship because their parents hate each other) and that's what I love about them. They rarely fight each other (except in the beginning) and they trust each other.
This drama was really beautiful.
Protect The Boss
Shopping King Louis
i agree with shopping king louis. they really were so kind to each other i loved it. also flower boy next door was good too the male lead was really nice 
my secret romance 
lets fight ghost 
its okay thats love
marriage contract