Like the OP I too cried as a child over Snoopy Come Home.
I tend to cry during any sad movie scene. The sappier and cheesier, the more likely I am to cry, which is embarrassing. I also nearly always cry through any childbirth scene, especially if it is, say, a dangerous birth out on the prarie or something. I guess it’s my female hormones? Speaking of which, if it is that time of the month even the most uplifting comedy will have some moment I will find tragic enough to sob over.
Welcome! Glad to have you aboard. 
Echoing what’s been said already, Up makes me cry whenever I *think *about it. The montage made me tear up a little, but him getting up, shuffling around and sitting next to her empty chair just kills me a bit inside every time I think of it. It especially makes me sad because it’s a stark reminder that this is really what most “happy ending” relationships look like at some point. Stay together for 50+ years only to end up sitting next to an empty chair with tennis balls on your cane. AAAUUGH.
The hardest I’ve cried has to be Beaches and Steel Magnolias, both which kept me crying long after I’d left the movie theater and returned home.
Simba laying by his deceased father in The Lion King breaks my heart.
On the flip side, I get happy tears at various parts of My Big Fat Greek Wedding each time I watch it. It’s my favorite love story.
I thought I was the only person who cried at the end of Rocky. Every damn time.
Went to see Phenomenon with my GF, and we were both unusually quiet during the closing credits, and admitted to each other later that we were each quietly blubbering into our popcorn.
the part at Rocky that always gets me is when he goes down in the 14th and Mickey tells him to stay down, but then he gets back up anyway. And the music is playing and it’s great. The music really helps.
The first time I watched it, I made it up to there thinking like “this is ok, but I don’t see why everyone says it is so great” That is the moment that changed my mind and now I love it.
I think we also need a Threads That Made You Cry, as I’ve gotten all misty thinking about some of the movies mentioned here. DAMN you people who mentioned My Dog Skip! I thought I was over it.
To me it’s the very final scene, when the announcer is saying Apollo won, and Rocky maybe doesn’t doesn’t hear it and doesn’t care anyway, because he’s won Adrian.
yeah I guess that part’s good too. I guess I just like the whole ending, start from the moment I mentioned going through to the end.
Angels in America, the Moon River scene gets me all choked up. Louis dancing with a healthy Prior, it’s such a bittersweet moment.
Here’s probably the silliest entry, but darned if it didn’t get me misty-eyed:
In Home Alone, when Kevin sees the scary old man hugging his family.
Saving Private Ryan.
Steel Magnolias.
Brian’s Song.
*Untamed Heart.
*
I think those were the biggest tearjerkers for me. I also cried at Bambi and Dumbo when I was a kid. I cried a LOT when I saw those.
Wait, what movie is it that has the people putting stones on a grave at the end? Is it Saving Private Ryan or Schindler’s List? I cried so much at that scene, as did many of the people around me. Maybe I cried at the end of both movies.
That’s Schindler’s List. I cry if I just hear the music (Yerushalayim Shel Zahav) that was playing during that scene.
I mist up far more easily than I like to admit, but * immortal beloved* always makes me sob. once upon a time, many moons ago, a good friend of mine and I both told another friend of ours that she should se it. Some Tyke later we stopped by her house and she and her boyfriend were watching it. Yep, we totally crashed their date night and stayed to watch it. As the credits rolled, the lone boy in the room turns and says “Well, that was co- og god you’re ALL crying?!?”
And We were.
Not a movie, but a TV show, and not one you expect to make you cry. The X-files.
Mulder, when he learns that indeed, his sister is gone. He enters the field and sees all the children that are missing, including the little girl who disappeared in the previous episode(it’s that tiny girl that looks up at him). Then…his sister, who runs up to him and they hug just for a moment. Oh, and the little boy holding his hand is the son of a man who is also looking for his lost son.
And they are all gone, truly gone. 
It’s the music, too. By Moby, oddly enough.
I challenge you to watch the first 2:30 of this clip and not at least tear up a bit.
Sorry for the crappy web site it links to. Only one I could find that had the right clip.
The Queen and Four Weddings and a Funeral
Must add to this. The recently aired episode of Glee where the mean lady coach’s sister dies. She was a Down Syndrome person. The soliloqy she delivers, talking about her sister, how they were together, how her sister was, the relationship, brought me to deep sobs. It was a painful bit of well written dialogue.
-sigh-
I hate to admit it, but the proposal and marriage vows in Howie Mandel’s Mobbed on Fox made me tear up. It was a one-off “special” that supposedly is coming back on air, but nothing’s scheduled.
Titanic, starting at the shot of all the people in the water, after the ship finally goes down.
Million Dollar Baby