My favorite of the WTF type mutators is Debug. I just love the look of the maps when they turn all white. Farty poopy is pretty funny if you have a good weapon for it. The animator head, Hey Frank or whatever is pretty funny too I just am moving so much I never get a chance to look at his face.
Ran into you on day one. I was telling my party, "That guy makes commentary videos for GCI!"
EDIT: If I could give you one tip it would be... POGO JUMP!
Just hold LB to constantly jump, if you move without looking 15 degrees left or right you will keep picking up speed letting you increase speeds constantly. Also pogo jumping is great regardless if you're turning, it's much faster than walking.