My wife's is a Honda TRX250es. It was about $3000 new. It was a 2005 hold over we bought in 2006. A very nice "small" 4 atv. I really like the looks of the Yamaha Wolverine. It comes in 350cc and 4 wheel drive 450.
If I was going to buy another it would probably be a Honda or Yamaha.
Wolverine
My wife's
http://powersports.honda.com/atvs/
http://www.yamaha-motor.com/sport/pr..._overview.aspx