I used google advanced search on swedespeed.com and got quite a few hits for XC90 tires if you want to do some reading to help you decide.
https://www.google.ca/search?q=xc90+tir ... -QOTg4G4CwLike Craig said, I usually got to Tirerack or Discount Tire look up my size and read the reviews to get an idea of what I want. I have the luxury of being able to buy online and have them shipped to Sweet Grass, MT combined with a tire guy that will install them locally. Some tire shops won't install tires bought elsewhere so you should check that out before online shopping and having them shipped. Also as Craig noted I run dedicated summer/winter tires as well on separate rims and highly recommend it over all seasons.