My choice was the .375 Ruger, as much for the Ruger Hawkeye African rifle I shoot it in as the caliber.
Now stocked in a McMillan McWoody, it is a light, handy, accurate, CRF rifle suited for anything big I might want to take on. It's going with me to Texas next month on a Nilgai hunt, and to Africa in August for African Lion.
With Barnes TSX 270 gr. bullets at 2800 fps, and great accuracy, it is about as versatile a caliber as you can find for bigger stuff, at short to longish ranges.

I'd rather be a free man in my grave, than living as a puppet or a slave....