I tend to watch really horrible movies over and over again whenever they're on tv, even though they are really bad. Usually they are made for TV movies for Lifetime or ABC Family or something. Two that come to mind immediately are:

My Fake Fiance
Holiday Switch

Some other movies I watch every time they are on TV (even though I think, as movies, they are HORRIBLE... but so entertaining nonetheless!) are:

27 Dresses
Made of Honor
Maid in Manhattan
Picture Perfect
Drive Me Crazy
A Cinderella Story
The Lizzie McGuire Movie
Confessions of a Shopaholic
Bride Wars
The Wedding Date
What a Girl Wants

Then there are GREAT movies I watch over and over again, like Sweet Home Alabama, The Wedding Planner, How to Lose a Guy in 10 Days, Two Weeks Notice, The Holiday, Wedding Crashers, Runaway Bride, My Best Friend's Wedding...