If you are looking for reliability, you can't go wrong with a Honda.
There are some articles out there comparing the Kawasaki 700, Grizzly 660, Rincon 650, and Sportsman 700. I think I have one of these articles in mag at home. If you would like it, I can scan and email it to you - just let me know.
I used to own a 400 foreman and currently own a 2002 660 grizz. I like the power, the looks, the suspension, brakes, etc. and have had no problems with it in 2 years.
I use mine to play and work. It does a good job for me at both.
You really need to decide what you want to use the atv for as this will help you make the right choice. Some of the above mentioned could be considered more fun than work atv's while others have said the polaris 700 is more of a utility atv.
Good Luck on your decision.