Full Throttle is probably my very favorite adventure game aside from GF. The atmosphere in FT is just magical and wonderfully cinematic. I also love the first 3 MI games. And IJ - TFOA. And DOTT. Ok, better stop before I list every LEC game.
This one is kind of an obscure one, but I really love Atlantis - The Lost Tales. Mostly for the incredible atmosphere again. Even with all it's flaws.
Then there's a couple of RPGs that I'd actually call RPG/adventure: Fallout and Fallout 2. Just great sci-fi adventures (with fighting of course, but turn based). Definitely among my all time favorite games.
Oh yeah, and Leisure Suit Larry 7 - Love For Sail is excellent too.