August is a great time to launch a game because its often barren of significant games, so no competition. Borderlands and Arkham Asylum both launched in August and did great.
...Borderlands released in October... Because I know I was in school for its release. But anyway I know what you're saying and I agree.
Yeah Bubbameister33 beat you to it. I think because Arkham Asylum and Borderlands were both $40 in Canada I was tying them closer in my head. Arkham Asylum and Bioshock would have been correct but I missed the ball.