I'll agree with everyone else... DEFINITELY get Paul Gilbert's videos. I would highly recommend his Intense Rock Vol 1 and Vol 2 videos... they are fantastic! His Terrifying Guitar Trip video is great too. And they are on DVD now. Highly highly highly recommend over any of the videos you listed in your poll. Petrucci's is good, but it's just the same chromatic shit over and over and over and over. At least with paul gilbert you learn a ton about speed runs, string skipping, sweeping, playing rhythm / solo grooves, etc. Just so you don't get stuck in the same alternate picking speed practice exercises, I would also recommend other videos by Vinnie Moore, Michael Lee Firkins, Michael Fath, Marty Friedman (his Melodic Control dvd is ABSOLUTELY amazing!!!!!), Frank Gambale, and Allan Holdsworth.