In no particular order:
Mase
Tone Loc
Biggie
LL Cool J
Q-Tip
"Best" is hard for me to quantify, but those are up there as my favourites.
In fact, I've just put out an album (13 tracks, 50 mins) of hiphop and RnB mashups.. check it out:
playlist,
download
with instrumentals from:
Jodeci, Jamiroquai, R Kelly, Notorious B.I.G., Mase, Naughty By Nature, Nelly, P. Diddy, Pharrell + more
vocals from:
Notorious B.I.G., Jodeci, Kanye West, Tupac Shakur, Montell Jordan, Boyz II Men, Nas, Mase, De La Soul, Tony Thompson, Ruff Ryders, Faith No More, Michael Jackson, Janet Jackson, Joe, Left Eye, Donnell Jones, Missy Elliott, Timbaland, Sisqo, Aaliyah, PM Dawn, P. Diddy, LL Cool J, 50 Cent, Grandmaster Flash, Snoop Dogg, Justin Timberlake, Vanilla Ice, Erykah Badu, 112, Q-Tip, NWA, Tone Loc + more
Hopefully I'll be able to listen to them next time I ski.... eating your own dogfood.