Tire Rack's Tire Decision Guide: Find the tire performance category that's best for your vehicle and the roads you drive on.

This is actually pretty cool, it lets you search by your vehicle type and then asks you a bunch of questions about how you drive and what type of environment you'll drive in and gives you some options and discounts. VERY COOL, give it a try.

When I chose off-road for the Trailblazer it gave me a list of tires ranging from $90 to $150, very cool.