Romantic Comedies is my favorite genre. While You Were Sleeping (Sandra Bullock) is one of my favorites and French Kiss (Meg Ryan). Both movies are lots of fun. I agree with Princess Bride, it's also a good one.
The Mirror Has Two Faces is another good one with Barbra Streisand and Jeff Bridges. Old old school, Pillow Talk with Doris Day.
Newer: This Means War with Chris Pine and Reese Witherspoon
When in Rome with Josh Duhamel
All great feel good movies but a lot of fun. This Means War is romantic comedy but also lots of guy action!