Well, brutha, you're kind of all over the place.
First, is the question: One GUN, One RIFLE, or one LONG GUN? Very different answers. The latter two suggest that you can supplement with handguns, and the second one suggests that you can supplement with shotguns as well.
Second, as mentioned, is it for every use under the sun, including all forms of self-defense? I'll assume yes on this one. That would rule out the drilling, assuming the question is one LONG GUN (the drilling is definitely otherwise the correct answer for all practical uses other than self-defense - make mine in 12 ga 3.5", .280 rem, and .223 rem, with .22lr and .22 mag chamber adapters).**
Next, you yourself gave TWO, not one, for your answer (unless a "61 grain penetrator" is from the ".22lr bolt" you mention - I don't know if this means you're adding a second gun which is a turnbolt in .22lr, or you mean adding a Ceiner-style kit TO the AR in 5.56x45, or you mean using a Ceiner-style kit period, withOUT ever shooting it in centerfire / 556x45 config - that's open to several interpretations). So which is it - two or one? Or are you asking One rimfire and One centerfire? Or what?
Just need to understand the question.
But if the question is "rifle", not "gun" or "long gun", and the uses include self-defense, but also all hunting, the answer is going to be, for me, a turnbolt rifle in a light config - preferably a scout type setup. Think "mountain rifle" or "mountain scout". 19 to 20" bbl, lightweight profile all around, chargeable by stripper clips (into a fixed 5 round mag), low powered fixed or variable scope, in the forward/eer/scout position. Chambering would ideally be .260 rem or 7mm-08, but other acceptable choices could include .243 win, 6.5 Creedmoor, .308 win, a few others. Might even could make a good case for .223 rem with a 7 twist. A really heavy gilding metal / monolith bullet, with brain shots, could bring down all but the largest African DG, and you could carry chamber adapters in .22lr and .22mag for subsistence survival, including shotshells. My choice would be .243 win if I had to press it into self-defense role too, but otherwise would be .260 rem. Add a ching sling.
Colonel Cooper wasn't whistling dixie when he came up the the scout concept - it's the right answer. Now an AR15 in something like 6.8 spc or 6.5 grendel or even .300 BLK is also a good choice, but I think it has to take a close 2nd place behind the scout due to WEIGHT. A lever or pump would even be in contention, but also end up being slightly behind due to weight, less accuracy, and less positive extraction.
If the question is one longgun, then that's a tougher call for me - it's be either the scout rifle still, or a shotgun (either semi or pump, preferably semi).
**PM me or ask if you want