I know it's atypical but the Nintendo Gamecube is my favorite of the "last generation" systems. It offered a return to the basics, to simplicity, while the others tried to make games more epic and complicated. Looking back, it was preview of Nintendo's direction to come with the DS and Wii.
Unlike Nintendo's previous entries, production of new Gamecube games halted almost immediately after the replacement system was available. Porting Gamecube projects to the Wii is apparently simple given their similar architecture. Even easier is slapping a new roster on an existing game engine. With little publicity, EA Sports produced a Gamecube version of Madden 08 along with all the "next-gen" editions. Some retailers declined to carry it, making it tough to find in stores, but it was there for anyone looking hard enough.
Power Rangers: Super Legends was almost the final Gamecube game. It was scheduled for release in November 2007 but quietly cancelled. Adding to the confusion, several online stores are still taking pre-orders for it.