Screwtape2
Blue Crack Addict
Lots of great ones have already been mentioned. Here are a few others:
Utopia Theme by Utopia (Todd Rundgren)
YouTube - Todd Rundgrens Utopia - Utopia Theme.part 2
Firth of Fifth by Genesis (Steve Hackett)
YouTube - Steve Hackett - Firth of Fifth Solo (live)
Time by Pink Floyd (David Gilmour)
YouTube - Pink Floyd - Time
Answers Questions! Questions Answers! by Focus (Jan Akkerman)
YouTube - Answers Questions! Questions Answers! - Focus
Utopia Theme by Utopia (Todd Rundgren)
YouTube - Todd Rundgrens Utopia - Utopia Theme.part 2
Firth of Fifth by Genesis (Steve Hackett)
YouTube - Steve Hackett - Firth of Fifth Solo (live)
Time by Pink Floyd (David Gilmour)
YouTube - Pink Floyd - Time
Answers Questions! Questions Answers! by Focus (Jan Akkerman)
YouTube - Answers Questions! Questions Answers! - Focus