Denver is a large city located in the center of Colorado, famously nicknamed the Mile-High City, due to it's altitude of roughly one mile above sea level. Denver has appeared in a number of games, mainly sports games due to the many professional sports teams in Denver.
Most of Denver's game appearances are due to it's sports teams, so listing them here seems fair.
Hockey- Colorado Avalanche
The Avalanche are two-time Stanley cup champions, in 1996 and 2001. The club plays in the Pepsi Center, located next to Six Flags Elitch Gardens in Denver
Football- Denver Broncos
The Broncos are back-to-back Super Bowl Champions, in 1997 and 1998. They play at Invesco Field at Mile High.
Basketball- Denver Nuggets
The Nuggets are Denver's basketball team, home of superstar Carmello Anthony. They share the Pepsi Center with the Avalanche as their arena.
Baseball- Colorado Rockies
The Rockies are Colorado's baseball team, generally known for being terrible, although they did make it to the World Series in 2007, before being swept by the Red Sox. They play in Coors Field