I want male MC, but will take female MC if it peaks my interest. So yeah, through misunderstanding or her falling for the other guy, I want to see an MC's love interest taken from him. (Not NTR though) And then he spends the story trying to win her back. I mean obviously she probably still has feelings for the MC, but goes with this other guy instead. I think a good example would be Yume de Aetera.

At one point Nagisa meets with her first love Minato and begins to fall for him again even though the entire time she's with Minato she's conflicted because she's in love with the main guy, Fuguno. It's funny, she has a huge distrust of men in the story, but in reality she's the one who betrays Fuguno.