The Colorado (Denver) Rockies won the National League Championship Series for 2007, taking four straight games from the Arizona Diamondbacks. The Rockies thus left the short list of franchises that have never won a league championship. The remaining perennial losers and also-rans are:
Seattle Mariners, American League 1977-2007 (best record in 2001, but lost AL pennant to NY Yankees)The Milwaukee Brewers (originally the Seattle Pilots) joined the American League in 1969 and won a pennant there in 1982. But the Brewers have gone pennantless since becoming a National League team in 1998.
Tampa Bay Devil Rays, American League 1998-2007
Texas Rangers (formerly the expansion Washington Senators), American League 1961-2007
Washington Nationals (formerly the Montreal Expos), National League 1969-2007
The Mariners, Devil Rays, Rangers, and Nationals (and their predecessors, if any) have not won a World Series, of course. Four other franchises have won league championships but have failed to win a World Series:
Colorado Rockies (2007)Related posts:
Houston Astros (2005)
Milwaukee Brewers (1982)
San Diego Padres (1984, 1998)
Can Money Buy Excellence in Baseball?
The Meaning of the World Series
Pennant Winner vs. Best Team