My personal all-time favorite is Green Crack. However, it's a clone-only strain, so ya gotta know the right people. Second favorite is Master Kush. MMMMMM soo tasty!
GC is approx 75%sat 25%ind, clone only. It has a very pungent, unique smell. GC when done right will have that unique odor that I adore! I've got some in my drawer right now actually! It is a very functionable high, but smoke too much of it, and it can lay you out!
Master Kush 100% indica (or close to it!). F1 cross of 2 Hindu Kushs. VERY POTENT. For me, initial effect is like a freighttrain to the dome. But after 5-10 minutes, it passes, and a heavy, couch-locking body high come on. AND IT STONED ME TO MY SOUL! Got some o'dat right now too! Had some this mornin, in fact!
I also love Pre '98 Bubba Kush, OG Kush, Haze strains (Skunk x Haze is killer!). Purps of course too! Grand Daddy Purps, Purple Erkle, Grape Ape to name a few.
Here's some pics:
Green Crack:
Master Kush: