Boy, this thread has really taken me down a long, memory lane. In my 60+ years of adulthood I've owned and shot well over a dozen different centerfire firearms, so many .22 rimfires that I lost count decades ago, though to my surprise I can only remember having owned a single .22WMR. I do suffer somewhat from Old Timer's Disease so I know I'll be overlooking a few in saying that the list definitely includes the following:
.22 LR, .22 WMR, .218 Bee, .223 Rem., .25-20 Win., .257 Roberts, .25-06, .270 Win., 7mm-08 Rem., .308 Win., 8x57mm, .35 Rem., .348 Win., .350 Rem. Mag. and a .416 Rem. Mag.
I'm also a little bit surprised in being able to only remember having owned just two of the centerfire chamberings in more than a single firearm, having had two each of the .308 & .348.
Like so many others responding to this thread I simply can't pick a single favorite but I can assign one or two of those cartridges as my favorites in the following categories:
.22LR & 25-20 for rabbits.
.218 Bee & .223 for varmints.
.257 Roberts & 7mm-08 for deer.
.270 Win. & .350 Rem. Mag. for elk.
.308 for target shooting.
.416 Rem. Mag. for caribou.
(The .416 won out only because it was the best I had for bear protection which, fortunately, we wound up not needing.)