I'll make this a separate post, since the other was exclusively LotR. Most other movies don't really get me, but songs are another story.
"Don't Take the Girl" by Tim McGraw gets me occasionally. Colin Raye's "Love, Me" is a guaranteed waterworks. Garth Brooks' "Belleau Wood," "The Dance," and others are very moving. Toby Keith's "Santa, I'm Right Here" and Shania Twain's "God Bless the Child" are the two Christmas songs that tear me apart.
I've cried at a few other movies, including Matrix: Revolutions, X2, LotR:FotR, and will probably (read: definitely) add to that RotK. A Beautiful Mind, the story of John Nash, gave me a few sobs and tears (just saw it for the first time about 10 minutes ago, literally). And, depending on which episodes, Star Trek, any series thereof, can have that effect on me, especially when Earth was destroyed in the most recent time-travel episode on Enterprise. The new Battlestar Galactica had me crying at a few points as well.
Yikes, didn't realize it was that much... Anyone got a mop?