For starters, I think the first deer rifle should be a nice HANDY rifle... So I opt out of any long action cartridge. Just adds extra bulk to me and for deer, there are many short action chamberings that will do the job just perfectly. With that said, I'll recommend the .243. I like the one I share with my younger brother, when he lets me shoot it.... I do like the idea of the 7mm-08 as well though. If the shooter can tolerate a bit more recoil, then by all means, but a bigger hole into your target.
"No experience is so conductive for steady and accurate shooting as the knowledge of the impossibility to escape by speed."
-Sir Samuel Baker