Lessee here . . . my opinions, woohoo . . . .
Best rapper? Eyedea, because of his awesome imagery and subject matter. He's close to the top for rhyming and flow but not the zdenith, though his unique brand of poetry is fantastic.
Best guitarist? There's no best guitarist technically, so it's all about musical acumen . . . and while he isn't the most influential, for all-out crazy innovation I hafta say Tymon Kruidenier. Exivious is just the coolest **** thing in the world.
Best drummer? I'm very very partial to Bill Bruford and Sean Reinert and Ginger Baker. They all have insane innovation and technical prowess.
Best bassist? This one is much, much tougher, and I don't really have a strong opinion, so Imma skip this.
Best keyboardist? Emerson and Rick Wakeman, absolutely. All the technical skill of Jordan Rudess (really, technical skill doesn't matter at all unless one doesn't possess any of it), but more innovative and awesome.
Best vocalist? My favorite isssss . . . ummmmmm . . . Elizabeth Fraser is absolutely amazingly awesome, and so is Neige and Annlouice Loegdlund and Ella Fitzgerald and Jon Haughm and Thom Yorke and Daniel Hakansson (from DSO) and Karin Dreijer Andersson and James Murphy and Kobi Farhi and Merrill Garbus and soooo many more people it's crazy.