When I was initially going through storyline, I REALLY wanted the full Battlemage set for my BLM, so I ran that an ungodly amount of times. If I was actively doing story missions I was running that dungeon. I gained at least 10 levels from running that dungeon by itself.

It got to the point where my wife, my brother-in-law, and I could almost run the dungeon without looking at the screen just based on how many steps we heard our characters take and the sound of the mobs we knew what to do.