Bagless ones are everywhere. The trick is to find one that isn't self-propelled.
And of all the vacuums that I've used (Eureka, Dirt Devil, Hoover, and Bissell) Hoover works the best, lasts the longest, and requires the least amount of maintenance. I have a Hoover right now, but it takes bags and that's a pain in the ass, with all the Cheerios I vacuum up.
I'd like to find a bagless/beltless, but I'll settle for just a bagless for the right price. I just need to find the time to shop around. I can't go without one for very long at all.