Dr. Julius Hibbert is the most promient, competent doctor featured on The Simpsons.  If we wanted to talk incompetent, we'd be talking Dr. Nick!  Hibbert is very good nature and always laughing.  Good guy.

Dr. Hibbert Quotes

Dr. Hibbert: You have twenty-four hours to live.
Homer: Twenty-four hours!
Dr. Hibbert: Well, twenty-two. I'm sorry I kept you waiting so long.

Dr. Hibbert: Um, your wife agreed that I should break this to you.
Homer: No need, Doc. I can read Marge like a book. (Looks at Marge, who is very glum.)
Marge: Hmm.
Homer: Ooh, it's good news, isn't it?

The Simpsons Quotes

Homer: (Wearing glasses) The sum of the square roots of any two sides of an isosceles triangle is equal to the square root of the remaining side!
Man: (From inside a bathroom stall.) That's a right triangle, you idiot!
Homer: D'oh!

Mr. Burns: Oh, and one more thing: you must find the jade monkey before the next full moon.
Smithers Actually sir, we found the jade monkey. It was in your glove compartment.
Mr. Burns: And the road maps, and ice scraper?
Smithers: They were in there too, sir.
Mr. Burns: Excellent! It's all falling into place...