Here are some randomly selected joke topics beginning with the letter 'D'
Double
Patient: Doctor, I keep seeing double.
Doctor: Please sit on the couch.
Patient: Which one?
Donkeys
How do you get five donkeys on a fire engine?
Two in the front, two in the back, and one on the roof going EE-AW-EE-AW.
Doorbell
Ever notice that when the doorbell rings, the dog's the first one to the door, but it's never for him?
Door
Knock, knock.
Who's there?
Doris
Doris who?
Doris open.
Come on in!
Donkeys
What is the hardest key to turn?
A donkey.
Donuts
Why did the donut go to the dentist?
It wanted to get a chocolate filling.
Door
Knock knock,
Who's there?
Heywood.
Heywood who?
Heywood you open the door?
Double
"Doctor, doctor< I keep seeing double."
"Take a seat please."
"Which one?"
Door
Knock, knock.
Who's there!
Ice cream!
Ice cream who?
Ice cream if you don't open this door!