You can find steam machines at all price levels. My suggestion is to avoid the steam mops because, in my opinion, they don't heat the water hot enough and don't have large enough water tanks for whole house cleaning. And many have a proprietary mop head cover, and they charge you a lot for extra ones.

The machines in the $400-$800 range have some things in common - stainless steel tank and a gauge that shows the temperature of the water in the tank and the tank pressure. Any of these machines should do a great job and last a long time. They generally have alligator clips on the mop head that clamp down on the cloth of your choice. I use microfiber cloths bought in bulk and change them out over and over again when I am cleaning a large, very dirty area.

I have the VaporClean TR6, bought used on Ebay. A friend of mine has another brand with a bigger tank - I can't remember the name of it. And the Ladybug is the well-known name in the industry.

I neither recommend nor not-recommend the machine I have because I have nothing to compare it to. No one seems to have done a comparison of their performance, maybe because the process of boiling water is so simple that they all will perform well. Once you get at the level of the stainless steel tank and the 2 or 3 liter size tank, you might then want to look at features such as the length of the electrical cord and ease of use of the handle.

My Vapor Clean TR-6 has two design flaws. The first is that you have to continuously hold down a button to get steam and your thumb get sore. Newer models have a better button system that stays on until you turn it off. It would cost me $80 to upgrade to that, so I use a rubber band to keep it on and spraying.

The other flaw is that it cannot be opened from the bottom. There is a drain hole and a nut, but the design of the machine doesn't give you room to get a tool down there to turn the nut. Maybe they have since redesigned it, but I have to turn the machine upside down in a sink to drain it. It is lightweight and not a problem, but still . . .

The 3-liter tank machine my friend has takes longer to heat up.

You may also want to check into a Hoover Floormate. I have one that I use on my hardwood and tile floors, I love it. They have one that comes with attachments for grout and small spaces (great for behind the toilet, etc.)