I have two 40mm, 3-9X Leupolds, a Vari-X II and a newer Vari-X 2. They seem to have the best optics for the "discounted" price of $300. I think the 3-9X is the best range for deer hunting in most situations, though some folks like the 2-7x and that would work for under-200 yard shots.
If I can't be with the rifle I love, I love the rifle I'm with!!