XLR, RCA or BNC?

I´m not searching to buy new gear - settled as is. Me and my friend was just talking about what would be the best termination, as different manufacturers and brands has their ´favorits´ in connections. We have no chance in trying them all ourselves ( xlr, rca, BNC ).

I´m fully aware that it does not matter ´much´. But if I hear a difference between switching brand powerplugs on my PC for example, there should be an audible difference between the chioce on terminations of signalcables.

The ideal thing was if someone had three equal cables with different ends. Xlr, rca or BNC. Had equipment to connect them all and do a simple A - B test. But that´s utopia for an answer.

We can settle for talking the terminations on digital cables, if it helps.

For digital cables the best is non of the above...

ST Glass is probably best (and I don't mean toslink).

From the electric point of view there should be no difference, assuming all have clean contacts. BNC and XLR lock in place, so they won't get pulled out by mistake if you move stuff around. XLR are big and clunky, which makes them easy to handle.

I'm not sure there is a "best" termination. I like XLR for my present equipment because it sounds better than RCA. I don't know why, it just does. If RCA sounded better I'd use that.