Hm. Well...

I really like most of Ghibli's movies. I don't think I've seen one of those that wasn't excellent, but my favorite was probably Princess Mononoke... That said! There are a few I haven't seen, such as Spirited Away, which I really ought to.

V for Vendetta is definitely one of my favorite movies as well.

An honorable mention to MST3K... If episodes of that still count as movies, then I'd have to say The Pumaman. Even on it's own merit it's hilariously goofy. Also, their episode of Santa Claus Conquers The Martians has become a Christmas tradition for me.

The Princess Bride is pretty excellent...

I'm sure there are others I'm forgetting, but, then, I don't frequently watch movies.