it's a tossup really, it all depends on your personal tastes and budget.
I have a 9mm AR15, the most fun semi auto I have and has the cheapest ammo.
I have a bolt action 45ACP, it's a conversion kit job and it fires but has serious ejection issues so it has little advantage over a break action. more expensive ammo, not a huge increase in FTLBs over 9mm but is strangely more quiet or at least comparable to 9mm. still working on a good sight setup so I can't vouch for accuracy at any range but I would wager that for hunting it would have to be restricted to muzzle loader ranges.
I have a marlin 44 mag that is a beast. I didn't even want it, I wanted a 357 but it's pre cerberus and the guy was asking half of what it was worth so I decided to risk it. Now I will never give this bad boy up. anymore the ammo isn't that expensive and I reload for it anyway which I think puts it below 9mm factory prices. the energy is decent enough to make a good deer rifle out to 150 yards and the very first shot I took with it vaporized a chipmunk at 20 yards... probably the moment that i decided that I would never give it up
if I had to pick just one I would have to decide whether I wanted a lever action or a semi auto, if I wanted a semi... I'd go with the 9mm, if I wanted a lever... 44 mag.