Most likely, yes.
I've played the following games in Vista 64-bit with virtually no noticeable hit in performance compared to XP:
Half Life 2 and Ep.1
BioShock
Company of Heroes (DX9; DX10 does yield a performance hit but the game does look much better)
F.E.A.R.
Oblivion
Medieval II
Team Fortress 2
The Sims 2 (required a patch to run in Vista)
Which games are you interested in playing?