TV shows where every episode has...
... the same writing credits? The only ones I can think of are COUPLING, EPISODES and THE I.T. CROWD.
The reason why I didn't ask "TV shows where every episode was written by the same person or people?" is because that could be confusing. For example, Larry David has written every episode of CURB YOUR ENTHUSIASM. However, he had co-writers during season 8, so the credits weren't the same.