I'd go .243 Winchester! "Magnumitis" is so addictive, you are probably leaning towards a 7MM Mag, .300 or .338 magnum!
But, if you are not wanting to hunt something bigger than Whitetail size game,try a .243! You'll realize that for deer size game, there is really no need for anything bigger! And, you'll wonder why you've punished yourself with heavy recoil and magnum prices for so long!