Question: movie where guy falls in love with best friend?
Answer: When Harry Met Sally... (1989) ... 
A Lot Like Love (2005) PG-13 | 107 min | Comedy, Drama, Romance. ... 
Definitely, Maybe (2008) PG-13 | 112 min | Comedy, Drama, Romance. ... 
You've Got Mail (1998) ... 
Zack and Miri Make a Porno (2008) ... 
He's Just Not That Into You (2009) ... 
Some Kind of Wonderful (1987) ... 
Best Friends (1982)