I'd second the .257 Roberts, 7-30 Waters, 7mm-08, .308, .30-06, and just about anything else up the middle range. Speaking of range--that's just it. Will you be hunting river bottom bean fields, wide western canyons, thick juniper thickets, eastern pine flats, thick grown-over clear cuts...........?
For myself, I found it nearly impossible to count on one rifle for every situation. In a quick pinch these days, it's going to most likely be a .444 Marlin with a Nikon Monarch 4x40 for the woody stuff, and a 26" M70 Classic Stainless with a Leupold 3.5-10x40 VXIII in 7mm Rem. Mag. With either of those, I have 99% confidence in my equipment for any situation I've found four-legged deer in. Throw in my 7-30 Waters Contender, and I'll go as far as 99.99%.
Good shootin', -7-