"pet" rifle action
Interesting question. I vote for the Mauser--chiefly because almost every bolt-action made in the last 100 years owes at least a little, in many cases a lot, to Paul Mauser's brainchild.
They're still available today--either as unissued military real Mauser, or commerical real Mauser, or commercial knock-off, for example the Ruger M77, or the CZ in 7.62x39. (That's the only CZ I've handled, and am not familiar with CZ's model numbers.)
There are only a few really brilliant originators in firearms design: Colt, Whitney, Mauser, Browning, Garand, Simonov, Kalashnikov, and Stoner come to mind. And the guy that came up with the flintlock, and the one who originated the percussion cap.