A buddy of mine told me to look at ground clearance and independent suspension. You may have less maintenance with a solid axle but from my few times riding them, you are pretty beaten up after a long day of trail riding. Far more comfortable with the independent suspension. That is just my opinion. As for a make or model, Arctic Cats use to have the most ground clearance, my buddies machine has served him well for the last 7-8 years. I believe he has the H2 700. Nice machine, uses it for plowing snow and trail riding. I have 2 other buddies with machines, one Honda and one Bombardier, both have been very happy with them.
Check out the link that K_F posted, Ask lots of questions, and you'll find something that you will be happy with. Personally I don't have one but someday....