AR-10 in .308 would be my choice. Big game and tactical value. A little pricey at first, but hey...you are going to keep this gun forever.

Click image for larger version. 

Name:	308-30-06-4.jpg 
Views:	61 
Size:	199.1 KB 
ID:	66570



http://www.luckygunner.com/lounge/308-win-vs-30-06/