YouTube is a treasure trove for rare recordings, live performances and just plain good videos. Please feel free to post any links you want to share and I (or any of the other mods, if they like) will update the original post (kinda like the freeware thread).
YouTube.
Try to post the actual video link, which is found to the left of the video player, and not your mile-long search string.
I'll get the ball rolling with a few of my favourites.
--------------------------------------------------------------------------------------
~~ LIVE PERFORMANCES ~~
At the Drive-In - Arcarsenal
A-Plus & Shlomo - Roni Size Medley
Dave Clarke - Dancing to Funky Town
De La Soul and MF DOOM - Rock Co Kane Flow
Dizzee Rascal - Live freestyle on 1Xtra
Gnarls Barkley - Crazy (Live at the MTV Awards 2006)
Gnarls Barkley - Crazy (Slower alternate version)
Human League - Being Boiled (1978)
James Brown - Get on the Good Foot / Soul Power / Make it Funky
Interpol - Leif Erikson
Interpol - Obstacle 1
ODB and RZA - Old video of some talent show or something.
P.J. Harvey - Rid of Me
Queens of the Stone Age - Hanging Tree
Rilo Kiley - Arms Outsretched
Thomas Dolby, Herbie Han..... Howard Jones, Stevie Wonder - Synthesizer Medley
~~ VIDEOS ~~
Air - Electronic Performers
Cabaret Voltaire - Sensoria
Captain Sensible - Wot
Freur - Doot Doot
Lily Allen - Smile
(EDIT: dead link again)
Lucas - Lucas With the Lid Off
Pendulum - Slam
~~ RANDOM, STUPID CRAP ~~
The Flaming Lips - She Don't Use Jelly (on Beverly Hills 90210, loller)
The Muppets - Fuck the Police
(EDIT: higher res version)