Here are some randomly selected joke topics beginning with the letter 'G'
Gladiator
Did you hear about the happy Roman soldier?
He was gladiator.
Glasses
Why did the teacher need to wear dark glasses?
Because she had such a bright class.
Gloves
Who has large antlers, has a high voice and always wears white gloves?
Mickey Moose.
Gnomes
Where do gnomes go to when they're feeling ill?
The National Elf Service.
Glass
Diner: Waiter, this water is cloudy.
Waiter: No it isn't, sir. It's the glass that's dirty.
Glasses
Tim: I hear you use three pairs of glasses.
Tom: That's right. One for reading, one for distance, and one to look for the other two.
Given
What can you keep even though you have given it to someone?
Your word.
Gnomes
Where do gnomes go to to get fit?
To an elf farm.