People who were huge fans of the MGS Solid Snake saga crying at the end of MGS4 makes sense...because it's the closure to something they've followed and loved for years. I know that feeling (though, not with MGS).

I cried at the end of FFX when I first beat it. I cried at the end of FFVIII when I replayed it a few years ago, mainly because of the nostalgia rush it game me.