Hey.
Here is a little spot I found when I were questing in Dragonblight.
The mobs have a respawn timer of 90 seconds and gives you ~10850 exp each pull.
This would give you around 433k exp / hour if you grinded them nonstop every respawn.
So if you are tired of questing you can go here for a while :)

Bare with my editing, since the movie was rushed to show some friends of mine.

Music:
David Baker - Devils Never Cry (Devil may cry theme)
Ratatat - Kennedy