I just re-read this thread. I think that some of the comments are tongue in cheek and some people aren't getting it, so like Bladebum did, I am going to respond again to clarify for newbies reading this.
I am not using .22 for pests anymore, because I want, or need, more power from a .25 caliber. For what I would use up to .22 for, I don't need or want that power. I am finding the .177 at 21fpe shooting JSB KO slugs to be plenty accurate and powerful enough with minimal ricochet potential, total energy dump, and no pass through. For pests, up to squirrel size, I am often shooting straight up and when I miss (it's happening more and more) I want the smallest thing flying through the air as possible. Get on Strelok and check out the ballistics of a .177 JSB MK3 10.03gr slug doing 965fps, or a 12.5gr NSA slug, a .22 isn't better, just different in a way that I find no advantage in, for my uses.
The new problem with this discussion is that there is actually three types of .22's now, the old ones that make up to 30fpe, the intermediates that hover between 30-50fpe, and the new ones that can pull off up to 120fpe. If you don't draw a line somewhere, have zero concern for pass throughs, cost, air usage, than yeah, .22 uber alles! At least for versatility.
I have an intermediate power one now and it performs in a different league than I am use to for a .22. I could use it for woodchucks but I just don't need to, I have .25's and a .30 for that already, that do the job easily. I am not saying bye-bye to .22 anyway, I just agreed with why Mike is, for his reasoning, and my favorite one caliber is .25, no doubt about that.
My favorite round for plinking sessions is the .22 because it does check all the right boxes. I easily shoot 3x more .22 than anything else, maybe more than that, and that's not changing any time soon. It is just big enough to smack reaction targets at 100y, not bad on air usage, quiet, 500 per tin, costs are not bad in bulk, and I can usually see it flying(.25 is better here). What's not to love.