I love this little exchange from one of my favorite movies, Harold and Maude:
Harold: "You sure have a way with people."
Maude: "Well, they're my species!"
I feel like that exchange sums up the whole message of the film: Love, be happy, form connections with people and don't take yourself too seriously.
As for my all time favorite film, I'd have to go with The Room. It's absolutely terrible, but in a way that makes it absolutely awesome and hilarious. Here's a scene from the film to give you an idea if you haven't seen it. I recommend it to everybody!
[video=youtube;mQ4KzClb1C4]http://www.youtube.com/watch?v=mQ4KzClb1C4[/video]