For salwater hoochies it's 2/0. 1/0 will do great too. I think 3/0 is too big (good for Chinook though.)
For Spin-n-glows though, I don't think a big hook will work well on the small sized Spin-n-glows.
On freshwater jigs for pinks, I've done terrible when the SHANK is too long to interfere with the action of the plastic part of the jig.
A pink salmon spoon I used recently came with a #6 hook standard. Not sure I'd put on a bigger one in that particular case, though, since I don't know what it's balance would be then.
When fishing saltwater, get a saltwater-rated hook.
Fat hooks are nice, because you'll probably lose fewer pink salmon than with real thin hooks, because of their soft mouths.
A little meat (when legal) on the hook usually results in them holding on longer, so you lose less fish that way. Same goes for a good shrimp scent on the lure.
I'd rather have a super-sharp hook that's a bit off in size, than the perfect-sized hook that's real dull. Many hooks out of the package are not real sharp, by the way. Put a triangle-cut into the point of the hook when sharpening.
Always checks the regs, but in the saltwater when I've legally used a TANDEM hook setup on hoochies (years ago) I lose fewer fish.