Nah, I don't know any sites, but I like some hip-hop music, Here is some of favs., and if you're after rappers about killing their moms and ex-wives, bitches hoes guns and money, not on my list, but here are some nice beats anyways:

Cypress Hill-"Tequila Sunrise" or "Dr. Greenthumb"
House of Pain-Fine Malt Lyrics LP
Funkdoobiest-Brothas Doobie LP
Jedi Mind Tricks-"Blood in, Blood out" or "The Worst"
Atmosphere-"Fuck you Lucy"
Dilated Peoples-Worst Come to Worst
K-OS-"B-Boy stance" "Clap Ya Hands" "Superstar No.0"

That's all I can think of right now, but get anything from Jedi Mind Tricks. They put retard 50cent to shame lyric and beat wise. Tears them apart with their "candy shop" bullshit crap.