I've been a fan of MF DOOM from way back when he went by the name of Zev Love X in KMD. King Geedorah and MIC, Metal Fingers and Victor Vaughn. Madvillain and DangerDoom... he is one of the most creative lyricists I have ever heard, as is evidenced in one track, "I Hear Voices", from the album "Operation: Doomsday". in that song, he successfully uses "Slobodan Milosevic" and "Ortho Trycyclen" in separate rhymes.
MF DOOM models his hip-hop persona off of Marvel Comics villain "Doctor Doom", hence the sub-pseudonym Victor Vaughn. He wears a metal mask when performing and will not knowingly be photographed without it.
He often fills his albums with samples from old Fantastic Four cartoons, or anything with references to Doctor Doom and villains. Some of his albums have not been welcomed by critics and fans of mainstream hip-hop because of this very feature; a couple of his releases may go on for 30+ minutes, with only 10 minutes of rapping. The rest of the album would be beats and samples.
The album "Vaudeville Villain", or "VV" - as it is sometimes known, is probably the most widely accessible release MF DOOM has put out, as there are fewer samples and the beats are more cohesive and less bizarre then have been on other albums. And every track, other than the short opening "Overture", features a vocal track.
His lyrics are outstanding, as always. I would provide a sample, but there is simply too much to condense, and singling out a couple of lines from any one song would be pointless. His lyrical prowess is something that should be heard. There are a few guest artists, such as Lord Sear and Creature on the track "Open Mic Nite, Pt. 2".
Some of my favorite tracks: "Lickupon", "Raedawn", "Saliva", "Mr. Clean", "G.M.C." and the hidden track "Change the Beat".
Other DOOM albums worth noting: "MM...FOOD?", "Madvillainy", "Operation: Doomsday" and "DangerDoom".