Microsoft Solitaire Collection includes a bunch of card game favorites, popularized by the Windows operating system.
There are are five games in the Microsoft Solitaire Collection: Klondike ('classic' Solitaire), FreeCell, Spider, TriPeaks, and Pyramid. All look and feel very similar to the original Windows versions and are, suffice to say, highly addictive. The game includes Xbox Live integration.
Microsoft Solitaire collection is a great timewaster, although it does put a strain on your battery.