RE: Most versatile
I would have to agree w/ either the 45/70 or .450 Marlin. I have a .450 Marlin and you can hunt anything you want in North America. It's bigger than you need for deer though it works good for them. Also any of the larger .30 calibers would work fine. The new .325 WSM looks interesting as well. I'm thinking about getting one though I really have no use for one.