Leagues

Combat Zone
Playing first person shooter, real-time strategy and flight simulation games. Includes results and information. Current game list includes: America's Army, Crimson Skies, Mechwarrior 3, Mechwarrior 3/UA and Wings of War.
http://www.czleagues.com

Cyberathlete Amateur League
A division of the Cyberathlete Professional League for North America. Leagues include first person shooter and real-time strategy games, includes team information and downloads.
http://www.caleague.com/

Cyberathlete Professional League
One of the earliest gaming leagues. Also hosts live events.
http://www.thecpl.com/

Ecliptical Realms Online Gaming Statistical Community
Playing first person shooter and space shooters, includes player and team rankings.
http://www.eclipticalrealms.com

GameBattles.com
Includes reviews, previews, screenshots and competition information.
http://www.gamebattles.com/

GetGosu Online Video Game Tournaments
League play for clans and teams. Also features tournaments for individual gamers. Supports First Person Shooters and Real Time Strategy games. Web-based software enables competitive online tournament play.
http://www.getgosu.com

Global Gaming League
Playing real-time strategy and first person shooter games. Includes forums, results, fixtures and replays for download.
http://www.ggl.com/

Major League Gaming
Hosts national and international contests among registered franchise teams. Professional Gamers on salaried teams.
http://www.mlgpro.com/

Mid-West Gaming League
Regional US Gaming League. Features downloads, articles, reviews, and forums.
http://www.mwgl.org/

SK Gaming
Provides news, clips and organizes tournaments for multiple games.
http://www.sk-gaming.com/