A good deal on a good vacuum for carpets - any ideas?

[Smithie]

I have a Miele for my hard flooring, and it's awesome, but not for the carpet. I am ready to buy an "upstairs" vacuum so our bedrooms can finally be clean. It will also need to vacuum the bathroom tile. It should not be a big heavy beast of a thing, because I am a wimpy little shrimp of a girl. 

I have about $500 to spend and was hoping to catch a post-Xmas sale. Anybody suggestions? 

[Lillitu]

Our dyson is the best vaccum I've ever used- and I have had many!

[texmati]

I really like my bissel prolite-- it's about $150. I went on about it post #5 on this thread.

[chely7425]

I have a Dyson, it is the best thing ever :) We have the allergy ones, i got it on sale after Xmas 2 years ago for like 300.

[zebra15]

Dyson was on sale, endcap at Target last week.  There should be some left at most stores. IDK what model it was tho'....