I have characters in quotation marks because I am thinking of characters whose everyday TV persona is funny. Best example is Jerry and Elaine were funny on Seinfeld, but Kramer, George, and Newman were all "characters".

My Top 10

1. Barney Fife
2. Basil Fawlty
3. Dr Sheldon Cooper
4. Cosmo Kramer
5. Archie Bunker
6. Frank Burns
7. Woody Boyd
8. Dwight Schrute
9. Gob Bluth
10. Randy Hickey