I usually use a 3,4,or 5 on the zoom swimmin flukes lol. Just whatever I grab from my vest first. IMO it's just whatever size hook you feel comfortable with that doesn't hinder the baits action. May not be the case for everybody but I RARELY ,if ever, miss a fish due to a smaller hook so it's just whatever fits. That being said, I always use a gamakatsu EWG if I'm t-rigging. That may also be debatable but it's the first "good" hook I started using, and thy fit my needs and brin in the fish! (They don't rust, stay sharp, and I can afford them!)
-Jeremiah