IMO, I've always gotten the best feel with using either 10's or 11's. I prefer elevens if I tune down a step, but that's just caused I'm used to thicker strings, but it's up to you.
i use 10's for E and D tuning with no problems at all.
P.R.S SE Custom

Line 6 Vetta combo
24 3/4" or 25 1/2" scale guitar? Either way, at least 10's. Too thick tends to affect my playing... even though I'm a bassist.
Quote by breakdown123
Is there such a thing as a heavy riff with out chugging on the e string?
Quote by Shred Head
You have an atrocious sense of humour!

Quote by StrayCatBlues
You win 100 hilarity points.

Spend them wisely.

Quote by GrisKy
you're a funny, funny man, chimp in a tux... funny indeed.
For my drop tuning guitar, I usually use Light tops/heavy bottoms. That has the G B and E strings as if from a 10 set, and the E A D as if from an 11 set.
Go with some GHS 11 Gauge Boomer strings. I really think those strings were made for downtuning! Also Ernie Ball Slinkys (10s or 11s) are great too. I use those and I tune down to D and they both work fine. Happy choosing!
i like using 9's for 1 step down (d standard) 10's for 2 step down and 11's for 3 step down because there is 0 resistance and you can bend a step or 2 more then normal cause of how light it is. there is 0 buzz on my guitars when i do that set up.
DR Tite-Fit 11-50 is perfect for me.
Gibson Les Paul Custom
Fender American Tele

Orange Rockerverb 50
Orange PPC412
Dean Markley Blue Steel 10-46 or 11-52 always worked for me. Good feel, good sound, great string life. Ernie Ball Power Slinkies, too.
Quote by invision2212
i use 10's for E and D tuning with no problems at all.

+ drop C