Edit: I fixed my typo in my op title. Thank you Nat for showing me how!
For me though, I don't know if I have a favourite romance/chick flick. I loved "The Notebook" and "The Princess Bride" was great. I also liked "10 things I hate about you" and others I can't remember.
I watch them sometime because the happy endings do make me feel good. I'm not in touch with my emotions and this is the little bit of sap that I like to fulfill that part of me. Sometimes, even this INTJ needs a good cry (from a movie). I heard that crying is good for you - every once in awhile. These chick flicks are usually the only time I really let loose and cry (if it's happy tears or sad tears for the characters in the movie).
And Recoleta, I totally agree, in Titanic, I think Rose could have moved over for Jack (or at least tried to) so that he didn't have to freeze to death. I actually hated how "stupid" Rose was in the movie - but maybe that's just me.