The following is a list of the five best on-disc songs in every GH game. Not as in "what do I want to listen to in my spare time", but as in "what songs would I play if I popped the disc in RIGHT NOW".
Guitar Hero:
1. Bark at the Moon
2. No One Knows
3. Crossroads
4. Godzilla
5. Frankenstein
Guitar Hero II:
1. Girlfriend
2. Rock and Roll Hoochie Koo
3. Dead!
4. Possum Kingdom
5. Hush
if you're playing on PS2:
1. Girlfriend
2. You Really Got Me
3. Last Child
4. Sweet Child O' Mine
5. Strutter
Guitar Hero Encore: Rocks the '80s:
1. Because, It's Midnite
2. Wrathchild
3. Play with Me
4. The Hellion/Electric Eye
5. 18 and Life
Guitar Hero III: Legends of Rock:
1. Cliffs of Dover
2. Welcome to the Jungle
3. Lay Down
4. Even Flow
5. Cult of Personality
Guitar Hero: Aerosmith:
1. Back in the Saddle
2. Rag Doll
3. Love in an Elevator
4. Bright Light Fright
5. Sweet Emotion
Guitar Hero: World Tour:
1. Do it Again
2. Demolition Man
3. Sweet Home Alabama
4. Crazy Train
5. La Bamba
Guitar Hero: Metallica:
1. Stone Cold Crazy
2. Sad but True
3. Stacked Actors
4. No Excuses
5. Fuel
Guitar Hero: Skipped Numbers are Edgy:
1. Incinerate
2. Fame
3. Woman from Tokyo
4. Blue Orchid
5. Sweating Bullets
Guitar Hero: Van Halen:
1. COME ON COME ON COME ON LET'S GO SPACE TRUCKIN'
2. Ice Cream Man
3. Double Vision
4. Runnin' with the Devil
5. You Really Got Me
Band Hero:
1. IF YOU WANNA BE MY LOVER YOU'VE GOT TO GET WITH MY FRIENDS
2. Y.M.C.A.
3. I Want You to Want Me
4. Paralyser
5. A Million Ways
Guitar Hero: Warriors of Rock:
1. SPIDER-MAN SPIDER-MAN DOES WHATEVER A SPIDER CAN
2. Money for Nothing
3. Cryin'
4. Burnin' for You
5. No More Mr. Nice Guy
games from best to worst:
1. Guitar Hero II
2. Guitar Hero Encore: Rocks the '80s
3. Guitar Hero: World Tour
4. Band Hero
5. Guitar Hero: Skipped Numbers are Edgy
6. Guitar Hero: Metallica
7. Guitar Hero: Van Halen
8. Guitar Hero: Aerosmith
9. Guitar Hero
10. Guitar Hero III: Legends of Rock
11. Guitar Hero: Warriors of Rock