I like many of those already mentioned. I did laugh with many of them, but I don't know if they would still make me laugh.
I am still laughing at The Goon Show [often repeated on Radio 4 Extra]. You can hear how much influence they had on comedians to come later. Victoria Wood still makes me laugh out loud, especially Dinner Ladies. She was genius in the way she gave her best lines to others.
I can't think of any old ones that haven't been mentioned above.
One who I still think is hilarious [but not yet dead, I hope] is Pam Ayres. They play her on Radio 4 Extra also and her theatre gigs are plentiful on Youtube.
Sara Milligan is another later one who is genuinely funny even when it is not intended.
I seem to have mentioned mainly women - but that is because all the males have been mentioned. Oh and the Goon Show was male and they went on to be funny on their own. So that balances it out.