For guitar and bass tabs - this site ROCKS!

HTML Goodies - This is where it all began for me

Audiogalaxy - this is the best for MP3's

Funny-sounds.com - This is where I got my animated GIF's from (got, stole - whatever!)

Scour.Net - This hardly ever works but has almost any MP3 you're after

mp3 Sound Direct Downloads - Don't get distracted by the fact that this one and the one below link to porn sites - you eventually find MP3's...really!