Dunno about the US but in Europe, one brand stands out as being the ONLY one which will lift cat and dog hair off carpets - Miele. (pronounced meeler)

You will have to define "good". There's SO much sleazy junk out there to buy that there's little quality stuff left over.

If you want a machine that will not break, that will pick up anything from thumb tacks to torn off Otter Pop ends to pennies to dried mud to a smashed stick of desk staples, and a lot of dirt too, get an Electrolux Sanitaire commercial. It's a plain upright, it's three hundred dollars, it's used by pretty much every commercial office cleaner and hotel maid in the universe, and it will last the rest of your life.

If you want something pretty, pretty is everywhere and you'll buy another way too soon.
Junk: Dyson, Dirt Devil, residential Hoovers, Miele, anything that swirls the air in a clear plastic tube.
Middling: Oreck Pro, Rubbermaid Pro, Panasonic Commercial.
Just plain proper: Sanitaire single motor bagged 7 amps or better.

Here is a link that might be useful: bulletproof

Hoovers are not junk. I once bought a light weight Oreck because I was tired of heavy vacuums. I took it back in a week. The guy told me he didn't think I would like it, light weight doesn't do the job at least back then. A heavy vacuum sucks down to the floor which is what you need for deep cleaning. My husband had a Kirby when we married and it was a good vacuum but only had 3 wheels and was always turning over. Other than that I have used Hoovers. I have a hoover wind tunnel and would buy another when or if it dies. It has lasted years and still does the same good job.

I appreciate your endorsement of the Sanitaire but, playing the Devil's advocate, if the requirements of commercial space aren't different than those of residential. While I appreciate that it can suck up a thumb tack or a stick of staples, I don't have any of them on my living room floor. My bigger question would be how well it deep cleans the carpeting, which is something that effects the longevity of the carpeting. How about pet hair, something not commonly found it commercial establishments?

I love my dyson and wouldn't get another brand if it ever broke. It's about 9 years old now , still as fabulous as the day I bought it ! Excellent suction , holds a lot of dirt , long cord , super easy to clean . So if you can afford one , that's what I reccomend ! :)
It has lasted thru 4 houses , 4 different types of carpet , one Rottweiler, a pug , bulldog and a cavalier pup , and two cockatiels . And a partridge in a pear tree. ;)

Well .... I'ld say you need to do the old fashioned "try me out" challenge.

You simply go into a vacuum cleaner retailer's business and ask to try out their various models .... If they agree to your trial, you proceed to put a line of dirt and other trash on the floor that you would expect to find in your worst cleanup nightmare, and then test each vacuum he presents on a different part of the line.

Make sure you step and scrub it into the test carpet well, because you know kids will do that with the dog and cat hair day in and day out before you can get to the mess ... Whichever vacuum does the job is the one you'll want to get! :)

Now ... if only the world really worked that way ....

(side anecdote ... read about this in reader's digest)

A door to door salesman came up to our house one day and managed to force his way into my living room. He was talking a mile a minute about how fabulous his brand new vacuum machine was and how it would clean up any mess, small or large, and then he opened his briefcase and dump a huge pile of dust and dirt in the middle of my carpet. He then proclaimed that if his vacuum didn't clean up every speck of that mess, he would EAT IT...

I handed him a spoon off of the dining room table, and then started to calmly tell the man who was turning red and beginning to panic, that my house doesn't have electricity.

The most important thing about a vacuum machine is the filter, not how much power it has.

A one horse power vacuum can have the same suction as a 1000 horse power vacuum, that is basic physics.

The balling ball suction demonstration is sales showmanship, it is not meaningful when you talk about vacuum cleaners.

dcarch