I personally like my .260 and .243

I used those as a hunting gun for about 10 years now.. They shoot remarkably flat (especially the .243, at one point I had an inch drop at 200 yards)

The actual power of the .243 is somewhat limited, the bullet is very small... but the muzzle velocity is extremely fast (hence flatness). .260 packs a bit more punch, but you get more drop at longer distances.

My 30-30 drops like a ROCK after 150 yards or so, but that same gun is responsible for decimating the american buffalo population back in the wild west days... hell, the indian population too 30-06 is a great choice as well... i guess it all depends on what you want..