Hand down its the Rainbow. It freshens up the air in a room and it smells 'clean'. As we left Texas behind I bought a rebuilt motor for the Rainbow in case we had a problem with the one we owned. 13 years later, no problems. Yes, it can be costly, but it holds up well. It can shampoo the carpet, or floor moving from one to another surface. Easy to use and move throughout the house. We have run it just to clean the air in the room, to remove six gallons of water from the floor when our refrigerator leaked water from the filter. Check with local vacuum dealers and see if they have one for sale, less than other models cost new. Rebuilt ones sell fast, so grab it if you get the chance. We are 76 years old and have used a variety of them, and would choose the Rainbow in a New York minute.
If you cannot buy from a reliable business that will back their machines. That is important part of a good choice to use as a reason to buy that machine.