We've always had pets and now we live on a horse farm with lots and lots of dirt so a good carpet cleaner is an absolute must for me. Clean carpets are one of the things I'm really passionate and particular about so I clean my carpets at least every 2 to 3 months, and oftentimes more frequently.
After going through several Bissell steam carpet cleaners, none of which lasted much past the 1 year warranty period, I splurged about 4 years ago and bought a Hoover Platinum Collection (Model #58100900- http://hoover.com/products/details/f8100900/platinum-collection-carpet-washer/ ) At the time, it was one of the most expensive consumer-grade steam cleaners on the market (I paid $400 for mine but I think they're a little cheaper now). They only have so-so reviews BUT Hoover offers a SIX YEAR warranty on this machine--no small appliance manufacturer offers more than 1 or 2 years, as far as I know-- and that 6 year warranty completely sold me on it. The machine cleans great. It's easy to use and I really love that it has a separate tank that holds clean water for rinsing.
Even though it is a great cleaning machine, the downside is it is mostly plastic and parts do break on a regular basis. However, this is where that 6 year warranty has more than paid for itself. I have had the machine "in the shop" several times for repairs, plus Hoover has totally replaced my cleaner twice so far in 4 years--no questions asked. Of course I still have 2 years left on my warranty so I have no doubt that based on my experience, I'll probably need at least one more replacement machine in the remaining warranty time. I would recommend that if anyone is considering this machine, you check to see if you have an authorized Hoover repair shop in your area. It is much, MUCH easier to let the authorized repair shop deal with Hoover, rather than you having to pack a broken machine up and ship it, plus I have found Hoover to be extremely difficult to reach on the telephone.
A couple months ago, I also bought a Bissell Spot Clean Pet machine that I really like for small cleanup jobs. http://www.bissell.com/spotclean-complete-pet/ We have a cat with a very sensitive stomach. At least once a week, she throws up and I got tired of dragging my big Hoover Platinum machine out to clean up these little spots. So far, I'm quite pleased with it. It's easy to use, lightweight and does a great job of getting the cat "yak" spots out.
As far as favorite shampoo for the steam cleaner, I've tried them all and hands down, I think the Woolite Oxy Spot cleaner is the best (also love the spot remover too). If you have any doubts about how good it is, check this out. One of our dogs made a huge mess that I thought ruined our carpet: http://mycottageofbliss.blogspot.com/2009/09/face-of-trouble.html
I don't use as much shampoo in the carpet cleaner as the manufacturer recommends--only a tablespoon or two, at most. Too much soap leaves behind residue in the carpet fibers that will attract more dirt to your carpet. I also put a little white vinegar in my clean water rinse tank and make multiple rinse passes over the carpet to help cut any soap residue left behind.
The best advise I can give you is to either put up with the dirt(bad idea) or get a commercial cleaning unit. by "commercial" I mean one that professionals use.
stay away from the machines that you see in the stores...they are only designed for light duty(light duty meaning, once or twice a year cleaning).
Where do you start to find such a machine? Either Google or consumer reports....personally, I'd prefer consumer reports.
Word of mouth can work wonders also. I wish you the best of luck Ms.Shari.
The best machine in my opinion will be Bissel big deep carpet cleaner since i was happy with the result it produces.But then again the hoover machine is not bad .And for the low price of hoover it does do the job right.But if you are looking for an indepth comparison between different carpet shampooers here is a link that may be useful http://thecarpetshampooer.com/
If you want to keep your carpet "alive" you shouldnt use any chemicals yourself. The best way is to order professional cleaning service, or buying cheap and small carpet cleaning machine like bissell spot clean pro, for review check http://cleanthiscarpet.com/bissell-spotclean-professional-best-portable-carpet-cleaner or http://www.amazon.com/Bissell-3624-SpotClean-Professional-Portable/dp/B008DBRFBK
If you really want to keep a well-maintained, clean carpet then you should check out the best carpet cleaners and also look at tips on cleaning upholstery and carpets which you can find here: http://www.carpetcleaner101.com