If new make sure to get a fuel injected model, they are not as finicky about stagnant fuel and run very well!
I have a Yamaha 550 Grizzly that has been the best I have had over the 30 years.
A good rack system is something to look at, some of those out there have limited space.

If you buy used, buy from someone that you think you can trust, a kid that mud rides all the time can destroy one in a year. A mature hunter that used it for normal trail riding, utility or hunting is much more likely to service the 4 wheeler.

Good Luck!