Personally I prefer Japanese audio with eng subs.
Pros
1. The voice actors are usually better with the Japanese audio, especially with some low budget animes.
2. Japanese vocal expressions are funnier.
3. Helps you learn Japanese.
4. Subs can explain gestures, actions, places, or behaviors that don't make sense to those who are not Japanese.
5. Improves reading skills
6. Makes you feel like a hard core anime addict, lol.

Cons?

This topic has been discussed many times in the AnimePaper forum. Please don't open up a new again.