Personally, I like the SUL stance (if you can actually call it a "stance") for just about everything, but especially when moving in close quarters. Its very versatile and allows you to protect the gun and shoot quickly from pretty much any position.
"If the rule you followed brought you to this,
of what use was the rule?"
“The enemy is anybody who's going to get you killed, no matter which side he is on.” - Joseph Heller