Walmart offers the Dyson V6 Cordless Bagless Vacuum for $299. Opt for in-store pickup to cut that to $211.10. (Amazon has it for the same with free shipping.) That's $18 under our February mention and the lowest price we could find by $88, outside of the mention below. (It's also the lowest outright price we've seen.) It features a motorized cleaning head, push-button bin emptying, detachable wand, and up to 20 minutes of cleaning per charge.

Update: Best Buy has it for $211.99 with free shipping.