I can tell you NOT to get a Bissel. We bought one used, and it's been nothing but trouble. We've spent more on repairs than we paid for it, and it still doesn't work right or stay fixed for long. It seemed to do a good job before, but now it's such a pain and doesn't clean very well, so we don't get it out much, which makes the carpet situation worse instead of better. We haven't been able to use the upholstery tools for years.
On the other hand, my in-laws have had a Hoover for ages and it still works great. When we lived near them, we had to borrow it all the time when our Bissel was on the fritz. I've been wanting to buy one for ourselves, especially since we moved far away from them.
On a side note, our first vacuum was also a Bissel, and I loved it. That was until its motor burned up just a month or two after its warranty expired. I called up a repair shop and he knew exactly what had happened, because he said they all burn up because of how they're made. He said I must have taken really good care of it to keep it alive as long as I did. Most of then burn up before their warranty expires, so they get replaced. What a great reward I got for taking good care of it! So after a year or so, we just had to toss it.
We replaced it with a Hoover, and have been using it for 5 years. We also have a Hoover FloorMate which has been going strong for years. I'm never buying a Bissel again!