It really depends on the lift too. Running an 8 inch superlift knuckle kit on my nnbs and I'm clearing 37x12.5 on 18" xd monsters. And the nnbs has alot more tire clearance issues then the nbs. Do some research on which lifts sit the tallest. Your could clear a 37x12.5 on a 7" with a leveling kit and some trimming. And I think trucks look the best when they are stuffed with big tires and smaller wheels. Big wheels look like the truck is a street queen.

 

This.

If you arent worried about rubbing, 35s.

My friend has 9.5" susp lift and 2" body lift on 35s on his 06 and it will still rub if you are hard on it. We hit a dip in the sand dunes going in a straight line and the tires hit the fenders. We were going pretty fast though, probably 80ish.

 

33's. 35's if you go with 8 inch wide wheels. Most people(and lift manufacturers) agree to go to a 37, you need 9 inches of lift, and then the 1/2 ton components become a major weak spot.