If you do not mind chinese drama i would say check it out:
Go go squid(slow romance till ep. 20 or something like that but after is is fluffy)
Intense love (Fluffy)
Flipped(drama but i loved the main couple)
General and I
Far away love(lots of drama but strong ML)
Memory lost(1 till 3) i think, it has been a while since i watched this one.
Put your head on my shoulder(innocent school drama)
Korean:
Clean with passion for now(No rivals, but some angst and a very steamy kiss ;)
Devilish joy
Golden bride( one of my favourit)
introverted boss
my secret romance
oh my venus(i loved this)
Shopping king louie
Something about 1 procent
Ugly alert( long but so good)
You could also check BL, a lot of them are good with out a love triangle.
Love me if you dare is very good, the romance is not super strong but is importent to the storyline.
I hope you find something to watched, i hope i did not make a mistake .Some i watched a long time ago.