Sliding Doors is a great one. I never heard of it before last night, when I was looking for something to "watch instantly" on Netflix. Maybe you never did either, since it came out in the same year (1998) as Shakespeare in Love. But you should see it. It's two stories, really, taking place with the same characters in parallel universes, one where Helen misses her tube train on the way home from being fired from her job, and one where she catches it, meets the attractive James on the train, and arrives home in time to find her parasitic failed novelist lover in bed with his old girlfriend.
The faithless lover, played by John Lynch, is so slimy you have to laugh, and his paramour, played by Jeanne Tripplehorn, is so nasty you want to hiss at her. James (John Hannah) is nice, but the villains get all the great scenes. You should see it if you're at all inclined to romantic movies. Or Gwyneth Paltrow movies.
