What is the best knock knock joke?

[Christopher]

I need to know some good knock knock jokes. Preferably some that are extremely funny and not just cheesy/corny, but those are welcome as well!

 

[TheSaint]

Knock, knock!
who's there?
Boo
Boo who?
Don't cry, it's only a joke!

Knock, knock!
who's there?
Earl
Earl who?
Earl be glad to tell you when you open the door.

Knock, knock!
who's there?
Emma
Emma who?
Emma bit cold out here, will you let me in?

Knock, knock!
who's there?
Howl
Howl who?
Howl you know unless you open the door?

Knock, knock!
who's there?
Cargo
Cargo who?
Cargo beep beep...!

 

[KiralLeeKimber]

knock knock
who's there?
Doris
doris who?
doris open come on in

knock knock
who's there?
bach
bach who?
bach bach i'm a chicken

knock knock
who's there?
loving
loving who?
loving you!

i found them in a childrens joke book hahaaha