Consumer Reports' best buy is the Kenmore (Sears) Progressive with Direct Drive 35922 for about $300.
I personally have a Dyson. This is the best vaccuum cleaner I've ever had. It's kinda spendy ($500.00) but worth every penny. I use it on all flooring. It cleans like nothing I've ever seen, and its easy to maintain and empty. Also awesome on pet hair and kid messes!
I have a built in vac. No need for hepa filters or vac bags all the dirt goes in a can in the garage and vents to the outside and the noise is out of the house. It's very powerful. It's the best.
Consumers Reports had a recent rating on vacuum cleaners.Check the local library, you can read it for free or Xerox the article. There is no point in spending hundreds of dollars more for a small margin of improvement.