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!

Horst: (Sinister) Okay, Mr. Burns, you win. But beware. We Germans aren't all smiles and sunshine.
Mr. Burns: (Sarcastic) Oooh, the Germans are mad at me. I'm so scared! Oooh, the Germans! (Hiding behind Smithers) Uh oh, the Germans are going to get me!
Horst: Stop it!
Man: Stop, sir.
Mr. Burns: Don't let the Germans come after me. Oh no, the Germans are coming after me.
Man: Please stop the "pretending you are scared" game, please.
Horst: Stop it! Stop it!
Mr. Burns: (Pause) No! They're so big and strong!
Man: Stop it.
Horst: Stop it, Mr. Burns.
Man: Please stop pretending you are scared of us, please, now.
Mr. Burns: Oh, protect me from the Germans! The Germans--
Horst: Burns, Stop it!