Gonna sound funny. But a Taurus PT-92 (an M9 clone). When I first got separated (around 1998), it was the only gun that I could afford. The separation was going ugly at that time. I had two kids and the ex-wife that I was paying for.
I still have that gun today. Believe it or not, it's still my bedside piece. Mainly because it has always shot everything that I've ever fed into it. Steel or brass. I don't care what the specs say.
Now don't get me wrong. I love my 45's, my 15's and of course ALL of my 10's. But that little POS 9 mm Taurus is still my bedside piece. After all these years....she still works.