Depends entirely on guitar.

On most guitars I use a custom set that has 9 tops but 11 bottoms, 9 to 50 or 52.
One Yamaha shredder I keep 9-42 and it's reserved for like crazy fast recording riffs, otherwise it's way too lax to play.

On a couple of 'em I have 9,5 sets (GHs) and on one gibby scale I usually use a 10 set. 13 on acoustic.

It's been getting this thin in recent years, when I had just a few guitars I used .11 - 52 sets on them.