At the moment...

1. Eno: "Burning Airlines Give You So Much More"
2. V-3: "American Face"
3. Kiss: "Shock Me"
4. Public Image Ltd: "Poptones"
5. The Cure: "One Hundred Years"

Runners-up

The Pop Group: "We Are Time", "Thief of Fire"
Joy Division: "Disorder", "Day of the Lords"

I'd ignored this thread because the concept annoyed me in a Guitar Player magazine sort of way. But I should have had more faith, this thread actually isn't irritating.

This is my top 5, but in no order of relevance. They're all great.

1. Neil Young - "Cinnamon Girl"
2. Slayer - "Reign In Blood"
3. Fatso Jetson - "Magma"
4. The Fucking Champs - "Never Enough Neck Pt.1"
5. The Kinks - "All Day And All Of The Night"

Damn that was hard. I love riffs.

what's a riff?

For some reason, the heavy rocking riff in Styx's "Lady" when it really "kicks in" sticks in my brain. I guess I'm fond of Thin Lizzy's "Jailbreak", also.

Nobody's Fault But Mine - Led Zeppelin
Highway To Hell - AC/DC
Lord of This World -Black Sabbath
Nosferatu Man - Slint
Gates of Heaven - Killdozer (it's actually the bass line that kills me)

The Boys Are Back In Town - Thin Lizzy
Reelin' In The Years - Steely Dan
Top Jimmy - Van Halen
Johnny B. Goode - Chuck Berry
Black Dog - Led Zeppelin

(Shock Me by KISS is another excellent answer)

Whole Lotta Love - Led Zeppelin
Pissant - Smashing Pumpkins (2:30 of pure RAWK)
Back In Black - AC/DC
Helter Skelter - The Beatles
Three way tie: War Pigs/Sabbath Bloody Sabbath/Hand Of Doom - Black Sabbath

Honourable Mentions:

The Shortest Straw by Metallica
Grace - Jeff Buckley
Purple Haze - Jimi Hendrix
Always On The Run - Lenny Kravitz (bitchin Parliament-esque horns, too)

1. The Ocean - Led Zep

2. Big Eyes - Cheap Trick

3. I Feel Fine - Beatles

4. Hot Smoke And Sassafras - Bubble Puppy

5. Burn - Deep Purple

Public Image Ltd: "Poptones"

I think Keith Levine nicked that from Steve Howe (Starship Trooper). That's my theory, and I'm sticking to it.

Rolling Stones Satisfaction has some good riffage