I'll second Imperial Hobbies, it not just the best game shop in the area, it's the best game shop I've ever seen.
The Comic Shop over on 4th Avenue has a good selection of stuff.
The up-and-coming new kid on the block is Drexoll Games a little further up 4th avenue. This is a gamers game shop and it shows in the love that Darcy and Tamara put into the place. Open Gaming, knowledgable staff, Tournaments, Game days, wicked selection, reasonable prices and snacks all add up to a place that has become something of a neighborhood fixture to the gaming community in a away that the Comic Shop never managed.
Tasmanian Connection is so-so (More Comics and Clix oriented)
Ive heard good stuff about Chaos Games out in New Westmister, but have never managed to get my ass out there.
Under no circumstances spend any time or money at The Games People in Gastown unless you are seeking insanely overpriced product from surly, unknowledgeable staff who seem to come across about a greasy as the stereotypical used-car salesman.
Email me if you want to meet for lunch or something.