I'm not that knowledgeable when it comes to rap but here are my favorites

N.W.A.

Wutang Clan

Outkast

Boogie Down Productions

Salt-n-Pepa

Ghetto Boys

8ball and MJG

The Fugees

Public Enemy

Tribe Called Quest

EPMD

Black Star
[Edited 3/21/08 18:30pm]

heybaby said:

I was waitin' for these guys to show up.

Also, Junior M.A.F.I.A., Do or Die, Above the Law haven't been mentioned.

GangstaFam said:

1.The crash crew
2.Disco 4
3.Jazzy 5
4.ATCQ
5.Treacherous 3
6.Flash & the five
7.Funky 4 +1
8.Black Sheep
9.Brand Nubian
10 Stetsasonic
11.Run Dmc
12 Cold crush Brothers
13.Fantastic 5
14.Fantasy III
15.Fearless 4

In no particular order (groups only, huh?):

A Tribe Called Quest
De La Soul
Public Enemy
Boogie Down Productions
Run D.M.C.
Whodini
Grandmaster Flash & The Furious Five
Wu-Tang Clan
N.W.A. (w/Cube; without was ass-out)
GangStarr
EPMD
Beastie Boys
OutKast
Eric B. & Rakim
Digable Planets

Honorable mention: Brand Nubian, Ultramagnetic MC's, Afrika Bambataa & The Soul Sonic Force, Mantronik

Public Enemy
A Tribe Called Quest
Boogie Down Production
Run D.M.C.
Beastie Boys
Cypress Hill
Salt N Pepa
N.W.A.
Naughty By Nature
De la Soul
Digable Planets
Lords of the Underground
Outkast
Brand Nubian
Camp Lo

I needs to do a part 2 for my shit:

1 - Camp Lo
2 - Superlover C and Casanova Rud
3 - Brand Nubian
4 - The Afros
5 - Poor Righteous Teachers
6 - GangStarr
7 - Above The Law
8 - Kid N Play
9 - Pete Rock & CL Smooth
10 - Main Source
11 - 3rd Bass
12 - Heavy D. And The Boyz
13 - The Pharcyde
14 - Black Sheep
15 - The Roots

Honorable Shout Out: The Jungle Brothers, The Heiroglyphics, Faze N Rhythm, Jurassic Five, L.O.N.S. Cypress Hill, Treacherous Three

MuthaFunka said:

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[Edited 3/23/08 8:32am]

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BOO YA TRIBE !!!! Those guys were heavy...