In alphabetical order my Top 5:
Jeff Beck
Roy Buchanan
Jimi Hendrix
Ted Nugent
Jimmy Page
Honorable mentions:
Eric Clapton
Stevie Ray Vaughn
Duane Allman was superb in his short time and would have definitely been on the list had he lived longer.
Jerry Garcia for his LONG jams and unique sound that I liked.
People I think are overrated (This doesn't mean they suck just I think they aren't as good as everyone acts like they are) Top 5:
Eddie Van Halen: He was exceptional and I'm a big fan but I feel like he never fully lived up to his full potential. He could have done so much more.
Chuck Berry: His songs all sound to similar to one another. And I'm fairly sure that quite a few of his songs are just Johnny B. Goode with different lyrics.
Keith Richards: The Rolling Stones are one of my favorite bands and he was a superb player/songwriter but no where near men like Hendrix, Page or Clapton where he is usually ranked.
George Harrison: He is ranked really high only because the Beatles were so popular. Again, not a bad player just not one of the greatest.
Kurt Cobain: I don't hear anything special at all when I listen to him. Sorry, I just don't hear it.
Most underrated (Yes, you'll have heard of most of them but I think they don't get the credit they deserve) Top 5:
Roy Buchanan
Mike Bloomfield
Ted Nugent: Everyone knows how awesome he is but won't admit it because they don't like his politics. It's rock and roll, not an election. Get over it.
Kerry Livgren
Allen Collins: Two words, Free Bird. I see alot of lists that don't mention him in the top 100 and Gary Rossington gets more attention since he's the only original member still in the band.