Rock Band brang exportable music into video games when they released Rock Band 2, allowing you to export all but 3 songs from Rock Band so you can play them in future Rock Band titles.
Guitar Hero 5 was the first game in that series to be a platform because of the exportability function for past games and the DLC with Guitar Hero World Tour was compatible with the game (apart from the Jimi Hendrix songs). Not all songs however will work, this is either due to license issues, financial issues, working on it, or they simply don't care.
GUITAR HERO SERIES
Guitar Hero World Tour
Aggro
American Woman
Angel*
Antisocial
Assassin
Beat It
Beautiful Disaster
B.Y.O.B.
Crazy Train
Escuela De Calor
Eye of the Tiger
Feel the Pain
Fire (Live at Woodstock)*
Float On
Foxey Lady (Live at Woodstock)*
Freak on a Leash
Freedom*
Go Your Own Way
Good God
Hail To The Freaks
Hey Man, Nice Shot
Hot For Teacher
Hotel California
If 6 Was 9*
Kick Out the Jams
La Bamba
Little Wing*
Love Me Two Times
Love Removal Machine
Misery Business
Monsoon
Mountain Song
Mr. Crowley
Nuvole e Lenzuola
On The Road Again (Live)
The One I Love
Parabola
Pretty Vacant
Prisoner of Society
Pull Me Under
Purple Haze (Live)
Ramblin' Man
Rebel Yell
Rooftops (A Liberation Broadcast)
Satch Boogie
Schism
Some Might Say
Scream Aim Fire
Too Much, Too Young, Too Fast
Trapped Under Ice
Vicarious
Vinternoll2
Weapon of Choice
What I've Done
The Wind Cries Mary
*=Incompatible DLC
Guitar Hero: Metallica
Albatross
Armed and Ready
Stacked Actors
No Excuses
Hell Bent for Leather
Stone Cold Crazy
War Ensemble
War Inside My Head
Toxicity
Guitar Hero: Smash Hits/Guitar Hero: Greatest Hits
Bark At The Moon
Barracuda
Beast And The Harlot
Carry On Wayward Son
Cherry Pie
Cowboys From Hell (Live)
Electric Eye
Godzilla
Killer Queen
Killing In The Name
Laid To Rest
Lay Down
More Than A Feeling
Mother
Raining Blood
Round and Round
Smoke On The Water
Stellar
Stop!
Take It Off
Take Me Out
Them Bones
Through The Fire And Flames
Thunder Kiss '65
Trippin' On A Hole In A Paper Heart
Unsung (Live)
Guitar Hero 5
2 Minutes to Midnight
All Along the Watchtower
American Girl
Dancing with Myself
Du Hast
Fame
Feel Good Inc.
Incinerate
Nearly Lost You
Play That Funky Music
Plug In Baby
Runnin Down a Dream
Sex on Fire
Song 2
Under Pressure
Why Bother?
Band Hero
Beautiful Soul
Like Whoa
Mr. Roboto
So Yesterday
ROCK BAND SERIES
Rock Band
Enter Sandman
Monsoon*
Paranoid
Run To The Hills
*=PAL Region only non export. This can be downloaded off the United States marketplace with a North America account however, but that would require the obtain of North American Points or Money, which would be purchased either with a North America Points Card or North America Credit Card. Due to PS3 DLC being region exclusive, however, they will not be able to play Monsoon in Rock Band 2, Lego Rock Band or future Rock Band titles.
This list will be updated when more songs are exportable and when more games come.