The Halo:Reach Stats API is a collection of methods to access the Halo:Reach game, player, and file information. With the API, users can browse through a player's history of games, return information on a specific file, return a list of rendered videos created by a player and more. The API uses both REST and SOAP protocols and responses are formatted in XML and JSON. Full documentation is not available.
Battlefield Bad Company is a first person shooter for Playstation 3 and Xbox 360. It keeps an amazing amount of statistics about its players, including a score, levels, a kill count, and many other things. The bfbcs.com site has a good listing of these, in a moderately accessible format. It also offers the Battlefield Bad Company Stats API, so programmers can add this functionality to their applications.