Love Call of Duty games. Although I wasn't too fussed on World at War and CoD3, but they weren't made by IW anyway.
Forza Motorsport. It's just class.
Gran Turismo. See above.
Project Gotham Racing/Metropolitan Street Racer (very much PGR1 for the Dreamcast). Shame Bizarre Creations have left Microsoft. Blur looks fucking shite.
Mass Effect 1 was brilliant, so I can already tell i'll love the next two