Comic Wonder does too. Mostly because we were scared of our a doctor as kids. (He was a pedophile.) Example:
Here on the Doctor Joke HQ, you will find:
We like doctor jokes mostly because of the surprise. Many of the funniest "I didn't think you were going there" jokes come from a doctors office.
The other part that makes doctors funny is we have all experienced them. Blondes, bars, lawyer, golf... chances are not everyone has a funny experience he or she can relate to. But with doctors, most likely everyone has been to see the doctor. And that can be funny.