my favorite knock knock joke:
me: hey, i gotta great knock knock joke for you
you: ok
me: ok, you start.
you: knock knock
me: who's there:
you:........
wilma who?
only because i dont think ive heard this one
Wilma finger do until I can get my pants down?
One of my favorite knock-knock jokes:
A: Knock knock
B: Who's there?
A: Interrupting cow.
B: Interrupting cow wh-
A: Moo!
It's funnier in person though. :p