I know, it's old and it's corny er, uh, cheesy.
A man walks into a bar with a cheese sandwich under his arm. "A pint of Guinness for me and the cheese sandwich," he says to the barman.
"I'm sorry, sir," replies the barman, "we don't serve food in here."
Try again:
A gorilla walks into a bar and says, "A scotch on the rocks, please." The gorilla hands the bartender a $10 bill.
The bartender thinks to himself, "This gorilla doesn't know the prices of drinks," and gives him 15 cents change.
The bartender says, "You know, we don't get too many gorillas in here."
The gorilla replies, "Well, at $9.85 a drink, I ain't coming back, either."