I totally cry at movies, even the ones that are obviously trying to make you cry. As long as the acting, production, and writing is good enough to lose myself a bit, I can totally ignore the fact I am being manipulated. I cry at so many films, it would be silly to list them.
When I was a kid, there was a commercial for something where a girl lost her cat and put up signs all over. There was really sappy music (IIRC, it was a little girl singing), and I totally used to bawl when ever it came on. There is a Peanuts special where Snoopy ran away/was kicked out of Charlie Brown's house and he had to make it in the cold, hard world. That used to upset me as a kid.
I cry at the end of almost every Cold Case. Not kidding.
I am a huge sap. I can't make a list of the most tear jerking movies because it would be too long. Most depressing, yeah something like Winter Passing might qualify, but not in that cathartic, cry your eyes out sort of way, but more in that soul sucking way. I really hated that film.
ETA: I am sure when we get around to watching The Road, that will be my top depressing film (if it's like the book). But if it's done well enough, I can enjoy it because I sort of watch films to spur emotions in me. Negative and positive. Sometimes it works (Down to the Bone is an example of a harrowing film that I love. Dead Man's Shoes is a good example of a British film that really is sad, horrifying, very violent though, with a lot of dark humour as well that is another favourite of mine), sometimes it doesn't.