I love Yngwie Malmsteen but he's far from the fastest. Even in his younger days, there were guys like Al DiMeola who could hold their own against Yngwie in speed if they so chose.
Angelo is a carnival act. lol. Seriously. When he plays normally, his picking is incredible. He implements strong alternate picking and even has economy picking under his belt to an extent but the double-guitar thing is a joke. It used to amaze the crap out of me but with what I know of guitar now and who all I know of, Angelo's double-guitar is a sloppy act. Everything is symmetrical and sloppy. He hits just the right notes to make it sound credible. That's not to say it's not a talent because the man can play pretty strong lead with both hands individually but go listen to guys like Stanley Jordan or Anthony Mazzella. THAT is true 2-handed talent. Not to mention all the other incredible 2-handed talents such as Justin King, Kaki King, Andy McKee, Tommy Emmanuel... the list goes on and on.
If you're looking for pure speed that blows Yngwie away, go listen to early Racer X albums. Paul Gilbert, in his prime, was just... WOW. If you want to take it to the next level with speed, go listen to guys like Ron Thal (Bumblefoot), Fabrizio Leo, Greg Howe, Richie Kotzen, Frank Gambale, Marshall Harrison, Jason Becker, Marty Friedman (Back in his Cacophony days with Becker, he was just insanely fast), Shawn Lane, Francesco Ferreri (who I can't stand but he's fast), Rusty Cooley, Richard Daude, Charly Sahona, Derek Taylor, Scott Stine, Scott Mischoe, Chris Impelliteri, Guthrie Govan, Buckethead (Yes, Buckethead... especially in his early days before he got famous when he was taking lessons from Paul Gilbert. WOW, he was insanely fast), Ron Jarzombek (of Watchtower and Spastic Ink fame), man, I could seriously go on and on and on and on for days. And yes, for as boring (although amazing-sounding!) as I find his composition to be, Michael Angelo blew Yngwie away in speed when he was in his prime. Have you heard John Petrucci these days? There are a couple of solos on the latest Dream Theater album that are just... man. UNBELIEVABLE. Mike mentioned Steve Morse and yes - he's absolutely a monster, too.
Now, even though neoclassical guitarists are a dime a dozen and they inevitably always get compared to Yngwie, NOT A SINGLE ONE of ANY neoclassical guitarist has ever composed as well as Yngwie composes, IMHO. The only other neoclassical guitarist I can stand (I mean, who I actually don't get bored listening to) is George Bellas. Check out his album Mind's Eye. Oh, and Vinnie Moore is a freakin' monster as well. Actually, as I think about it, there are a few I enjoy... Michael Romeo (of Symphony X fame) has an old solo album that's really awesome. Guys like Joe Stump bore me, though. I know the guy is reputable and he's an instructor at Berklee but his compositions just really bore me. Here again, though, this is just a matter of personal preference. To a lot of people, neoclassical is neoclassical but that's a ridiculous thought to admit thinking if that's the way you see it. You simply need more exposure but if you're not that interested in the style, then it's best to just go with what you know and love.
Anyway... There are waaaaayyyy too many amazing guitarists out there and they're all very different. There is no greatest, I don't feel. There's only guitarists you like and guitarists you don't like. Yes, some are better than others and some are memorable for their music but simply put, there are just too many great guitarists out there to find out about for anyone to limit themselves to feeling like there's a greatest. That's how I feel about it. Being able to choose a greatest is like saying "I give up looking for someone who writes music that I'm going to enjoy more than so-and-so." Expand your horizons! Your favorite music is waiting out there for you - you just have to find it. =) That's not to say we all don't have our classic vices which, for me, is Rush, hands-down.
I think you guys get what I'm saying, though.
-Stephen