EDIT: couldn't get the damn youtube embed to work.
I normally hate rap, but I love Movits. I guess they're more of like jazz/swing/rap, but whatever. I bought their album today and I'm loving it. The music in the background actually has some composition to it instead of just a single beat being played under some lame samples like radio-rap. They were on the Colbert Report the other night.
My favorites are the Death Row era, so Ice Cube, Dre, and Snoop are obvious. Past that, Busta Rhymes' 'When Disaster Strikes' is amazing, his first few records were.
DMX. Eminems first two records (What the fuck happened after that, Marshal?) Public Enemy of course. Buck 65's early work was great for a white canadian.
Makaveli- The Don Killuminati: The 7 Day Theory Cypress Hill- Black Sunday House Of Pain (Fine Malt Lyrics) B.I.G.- Ready To DIE Beastie Boys- Paul's Boutique
I'm mostly into the older-type stuff, I'm just a bigger fan of it personally. So for that type, I'll recommend A Tribe Called Quest (The Low End Theory), De La Soul (3 Feet High and Rising), Ghostface Killah (get Supreme Clientele and Fishscales), GZA (get Liquid Swords), Madlib (Shades of Blue), Madvillian (Madvillainy), MF Doom (MM.. Food), Mos Def (Black on Both Sides), The Roots (Do You Want More?!?!?!!, Illadelph Halflife, and Things Fall Apart), Nas (Illmatic) and The Wu-Tang Clan (36 Chambers).
If you're into newer stuff, Doomtree, Deltron 3030, Del Tha Funkee Homosapien, P.O.S., Immortal Technique, Copywrite, CunninLynguists are particularly good.
Viktor Vaughn DMX's first album (phenomenal, really) - It's Dark and Hell is Hot NAS - I am Notorious BIG - Life After Death Eminem's first 2 albums Anything by Mystikal ( he had a few albums out already before he got big )