Interestingly, right now my favorite drum solo is the little ten bar solo that Steve Gadd plays on the end of Fifty Ways to Leave Your Lover, from the Concert in Central Park.  It is so simple, yet it is perfect.  

Great Solo - I just downloaded it.
I also like anything by Buddy Rich

You hit my two favorites right on the head. As soon as I saw this question posted those were the two that came to mind first. All though Buddy has mesmorized me with some incredible solos as well.

   I saw Steve Smith last October w/ his Mike Zilber/Steve Smith Quintet (Dave Liebman was a guest and ripped it up!) and he did a solo where all the musicians walked off the stage while he teared the roof off the place!

    He started with timpani mallets and then went into the thing you were describing Mr. Drums where he did a roll on one hand (triplets this time instead of 16ths) and then did the most amazing solo I've ever seen or heard! And then, when he got bored of that, he started playing the triplets on his bass drum as well to match the snare drum and then soloed over that with his left hand and his hi hat! And then (yes there's more) he pulled sticks out from behind him and switched to those without even skipping a beat. And all of this was done at a ridiculous tempo.

   When he was playing the one-handed triplets and the bass drum triplets together I can honestly say that he was playing faster than I've ever seen anyone play with one hand and he was doing it with complete control and soloing over it.

   Amazing!!!!

ONE of my favorite solos is "The Drum Also Waltzes" by Max Roach.  If I had to choose only one word to describe Max's playing (not only in this piece but in all his work), that word is ELEGANT.  His fluidity and independence are amazing.

Well i'm gonna say a Tony Royster Jr. solo that i downloaded. He was only 12 at the time, and what he played was so impressive. One of the coolest thing I saw in a long time.