It would be hard to buy a bad 4-wheeler nowadays. As little as 5 years ago I would have argued different, but now most all have their good and bad points.
I've got a Honda '95 300 4x4 that I bought new. 10 days after I got it, I put it through the ice in front of my house. I found out they float, only upside down!
It was in the water for over 4 hours before we finally extracted it. After draining the fluids and replacing them all, the bike started right up. ^ years later, I can honestly say it has NEVER let me down.
I work the absolute HELL outa my Honda. It gets used almost every day: I plow snow with it all winter; use it to tow stuff around the yard, and it is indispensible around the hunting property.
Because of all this, I'm particular to Honda. My next machine will be the new 500 Rubicon. It is the ONLY ATV with a true automatic transmission. Honda uses a fluid system much like automobiles, while all the rest use a belt system identical to a snowmobile drive. Obviously these are prone to eventually wear out.
And no matter what you buy, a winch is an absolute must!