I'm a Winchester Model 70 fan, but now with their demise, you'll probably be relegated to finding a good used one (they're out there).

That being said, I have purchased a Ruger 77 in 416 Rigby which I'll hopefully be using on a Cape Buffalo in Namibia's Caprivi Region in August of 2008.

I feel both of the rifles listed above fit the bill for providing a lot of bang for the buck.