A good, quality sampling of definitive songs for those that have forgotten what rock was meant to be.
Courtesy of the following sites, none of which have a good selection:
AOL Music
MTV
VH1 Classics (they censor)
YouTube (only when nothing else available)

Metal

Queensryche

• Revolution Calling
• Suite Sister Mary
• Eyes of a Stranger

Metallica

• Enter Sandman (Live)
• Whiplash (Live, Jason Singing)
• For whom the Bell Tolls (Cliff)
• For whom the Bell Tolls (Rudy)

Megadeth

• Peace Sells

AC/DC

• You Shook Me All Night Long (Live)
• Thunderstruck (Live at Donnington)

Judas Priest

• You’ve Got Another Thing Comin’ (Live)

Warlock

• All We Are

Scorpions

• Rock You Like a Hurricane

Dio

• Rainbow in the Dark
• We Rock
• Man on the Silver Mountain

Balck Sabbath (with Dio)

• The Mob Rules

Ozzy

• Crazy Train (Live)

Accept

• Balls to the Walls

Quiet Riot

• Bang Your Head

Twisted Sister

• We’re Not Gonna Take It

Savatage

• The Hall of the Mountain King

Led Zeppelin

• Black Dog (Live)

Neo-Classical Fusion

Yngwie Malmsteen

• Trilogy Suite – Op 5
• Heavy E Phrygian

Progressive

Rush

• Distant Early Warning
• Tom Sawyer

Yes

• Roundabout

Kansas

• Carry On Wayward Sun

Alternative

10,000 Maniacs

• These Are Days

REM

• The One I Love (AOL Session)

Concrete Blonde

Everybody Knows

Heal it Up

Joey

Still in Hollywood (no video)

Fiona Apple

• Paper Bag (Unplugged)

Punk

The Sex Pistols

• Pretty Vacant (live)

The Clash

• Rock the Casbah

The Ramones

• The Blitzkrieg Bop (Live)

Green Day

• American Idiot
• Holiday
• St. Jimmy

New Wave

Devo

• Satisfaction

The Pretenders

• Middle of the Road

U2

• I Will Follow

Industrial

Ministry

• New World Order (NWO)

New Metal / Hardcore

System of a Down

• Aerials

Korn

• Freak on a Leash

Rockabilly

Multicategorical

The Cult

• Love Removal Machine

Uncategorical

Rage Against the Machine

• Guerilla Radio

Primus

• Wynona’s Big Brown Beaver