I haven't cried in a few months I don't think, but I'm definitely one of those emotional guys that will cry a lot.  Not so much with songs or movies, but if it has to do with something I care about the tears just don't stop (even if it's something stupid like I break/lose something).  This is why I never gave Davis a hard time for crying during a game, it's completely understandable.  It actually happens more with TV shows because I feel like I know the characters personally.
When I was younger I would have a hard time not crying if someone started a fight with me.  I don't know if anyone else has experienced this, but I would just get so emotional.
As far as Marley, I'm sure I would've cried if I watched it.  There's just something about sad animals that gets me upset (kids too).  They're just so innocent.
And for the record, I cried every night for at least a week when things in a long relationship fell apart.  I think love is something that will always make a guy cry.