Top 10 film catchphases....

Arthur: "Where's the rest of this moose?"

 

Elwood: "We've got a full tank of gas, half a pack of cigarettes, it's dark and we're wearing sunglasses."
Jake: "Hit it." - from The Blues Brothers


Merlin: "Looking at a cake is like looking at the future. Until you've tasted it, what do you really know? And then of course, it's too late. Much too late." - from Excalibur

 

Hope this wasn't posted before, specially not by me:

"I'm walking here!" Ratso Rizzo (Dustin Hoffman) in Midnight Cowboy.

 

Followed closely, of course by:

Arthur (after a joke bombed): This is a tough room. (And then, to the moosehead) I don't have to tell YOU that.