Frets on Fire
“Frets on Fire is a game of musical skill and fast fingers. The aim of the game is to play guitar with the keyboard as accurately as possible.” – Source
Frets on Fire is an amazing program that allows you to play a Guitar Hero like game on your computer without spending $80-100 on the guitar and game. This game is free and guess what! You can put ANY songs you want on it! I have found a good collection of songs you can download for it and the link is below. As for the game, a Free download can be found below as well.
Enjoy rocking out on your keyboard!