Mine is Will Smith, but since he is more hip hop/r&b, I have got to say P. Diddy, he has got skills.  I also like Ja Rule.
Down with Snoop Dogg and Eminem, I really don't like how they disrespect everything in their songs.  I like Nelly, even though he doesn't rap all the time.  B.I.G. rip.

I like Ja Rule, Nelly, & OutKast.

Ludacris, Mystikal, & Eminem are also good rap artists, although in Eminem's case, I don't agree with some of the disses he makes.

The one, the only, Tupac Amaru Shakur, followed by:

Dr. Dre
Snoop Dogg

And basically all the rappers who used to be affiliated with Death Row Records.

no order

Eminem, D12, Royce da 5'9, Proof
Outkast (the first album is the best)
2pac, Biggie, Eazy-E,  NWA
Dr. Dre, Snoop, Xzibit
Dayton Family, Bootleg, Shoestring, Jake the Flake
Methodman & Redman, Benefit
Da Nasty Boys, 3rd Degree
DMX, Eve, Jadakiss
Pharaoh Monch, High & Mighty
Ludacris, Ja Rule, Nas, 50 cents
SPM, Nb Ridaz,

Nelly sucks now
cannot stand P. Diddy, ,but he does make a few good songs
I despise Will Smith

uh thats all I can think of for now

I think the only two rappers I cared for were Hammer (OK, so he sampled Rick James' "Super Freak" for his biggest hit, "U Can't Touch This") and Coolio, the latter because I thought he was funny (although "Gangsta's Paradise" was downright serious).

Will Smith, DMX, Nelly.  But I don't listen to much rap.

I don't listen to modern rap at all.  I do like a lot of the "old school" artists, but it seems Will Smith is the only one who has recent stuff out.

I like Whodini, Sugarhill Gang, Run DMC, and most of the others who first made it big in the 80's.

I prefer old school myself:

RUN-DMC
Doug E. Fresh
Slick Rick
Whodini
Sir Mix-A-Lot
Rakim of Eric B. & Rakim
Chuck D. of Public Enemy
Heavy D.

As for today's rap, from a lyrical style POV I like Eminem and Outkast...can't say I listen to them much, though...

I like a little bit of the ol'school myself including:

YOUNG MC
TONE LOC
WILL SMITH

  -howard-  8)

Ja Rule , Nelly, and P. Diddy are not even real hip-hop. My Top Rappers of All time list-1.) Rakim 2.) Tupac 3.) Nas 4.) LL Cool J 5.) The Neptunes 6.) Outkast. 7.) Jazzy Jeff and Fresh Prince 8.) Beastie Boys. Other rappers I respect but haven't listened to alot of their work: Public Enemy, Bone Thugs N' Harmony,  Jarrasic 5, and Wu-Tang Clan, Mobb Depp, and Naughty By Nature.

Wierd Al Yankovich ;) I just love how pissed "Coolio" got after Al did "Amish Paradise"  ;D

I like old and new school rap/hip hop. Here they are.

Grandmaster Flash & The Furious 5
Salt 'N Pepa
Yo Yo
The Fat Boys
Run DMC
N.W.A. (including all its memebers that went solo)
MC Eiht & Compton's Most Wanted
Scarface & The Geto Boys
Public Enemy
Ice - T
Sir Mix A Lot
Luke & The 2 Live Crew
2Pac
Eminem
The Beastie Boys
Outkast
DMX
Wu Tang Clan
Biggie Smalls
Fat Joe
Big Pun
Foxy Brown
Snoop Dogg
Busta Rhymes

Ummmm....

I like almost any rap that came out prior to Dr. Dre an Snoop dog, Although I never liked NWA or Easy E.  I like fun rap songs.

Eminem
Nelly
Missy Elliott
Eve

Eminem and Will Smith. Dre's pretty good. I ike his songs Still D.R.E and Forgot About Dre that features Em.

Mostly old school rap artists.  8)

Run DMC
LL Cool J
Salt N' Pepa
DJ Jazzy Jeff & The Fresh Prince
Rakim (Eric B. & Rakim)
Tone Loc
Grandmaster Flash & The Furious Five
Biz Markie
Coolio
Whodini
Kurtis Blow
Beastie Boys

Outkast, De La Soul, Nas, Eminem.

Wu Tang Clan (older stuff), Maestro Fresh Wes (older stuff), Cypress Hill, Beastie Boys, House Of Pain, Rascalz

My tastes in this area are a bit weird and long-winded (as usual :p ::) ).

Dead Prez - for Politics
Tystion - for Beats, Originality and Politics (if a bit dodgy)
Eminem - just scrapes in for Offensiveness (Offensivity?)
Crass - i know they ain't rap but if anyone's heard Smash the Mac, i'd say it was pretty much delivered like rap.  So they are in here for Delivery...i'm interested in hearing Steve Ignorant's (the lead male 'singer') 'rap' album - should be interesting if a bit cringe-worthy.
The Streets - O.K. so this is technically Garage and the bloke does 'spitting/MCing' rather than rap but his Rhymes are pretty good and his Imagery is interesting.
MC Pitman - for his total lack of rap 'ego' and his great 'Disses' and his dry deadpan sense of Humour.
Brainpower - the bloke looks like a reall geek but his Rhymes are good (17 lines of rhyme in a row) and his Delivery is amazing in parts - Nul points for being featured on a 'joint' by Nas - euch.

i don't have a favorite rap artist (do the beastie boys count? ;)), but my favorite song is "baby got back" by sir mix-a-lot. :D

I don't really listen to Will Smith, DMX and Nelly anymore; some of Nelly's songs are alright and so are Will Smith's (if you would call these guys rap).  I don't listen to much rap though... Run-DMC is cool... so is OutKast.

Oh er . . . Rap isn't my thing but I do like MC Hammer (his samples were o.k - 'Superfreaks' by Rick James/U Can't touch this and 'When doves cry' by Prince/Pray).

Grandmaster Flash and the Furious 5 gets the respect from me. He kept it real as far as I am concerned.

Nas, Rakim, LL cool J, Jazzy Jeff and Fresh Prince, and 2 Pac.

No offense, but to my mind "rap" and "artist" in the same sentance is almost as big an oxymoron as "military intelligence" or "our smart president".  Of course this is personal preference - ahhh, Bach  ;D