the first one is the best.
the second and the third are tied.
I can see that you are trying hard in blending pictures in the 2nd. though I think rather than soften the edges, you should try to make the two characters blend in background somehow and try to lessen the smooth look on your poster abit more.

about the third one, I think rather than focusing on the letter animation down there, how about making animation on the lightning that sparks between them instead? and find some pics of them glaring or barking each other heads off will kinda improve the tension between them too. after all, this is a Rom-com, isn't it?

The first one is really pretty!! <3 I also like the 3rd one because its funny. Great job ^^

Wow i like the first one!! (Y)

wow~ the second poster is so nice <3
did you put tears on kyuhyun's cheeks though o u o it looks nice lol