I started to appreciate stand-up comedy a lot more after realizing just how much effort goes into delivery. It's almost uncanny to watch a comedian perform the same routine twice, because their timing is so consistent.
Here's a good breakdown of a Louis CK joke: https://www.youtube.com/watch?v=ufdvYrTeTuU
Jerry Seinfeld also gave an interview with the NYT about the process — I think Jerry is a good example because so much of his comedy depends on the delivery.