I've been sewing a lot of denim lately, and my Pfaff 1475, although a normally reliable machine, was struggling with the layers - 8 at some corner points.
So, I tried my Singer 611g, which I usually use for buttonholes. It went through the layers like a knife through butter! So I was able to finish off all my aprons with beautiful stitching.
I would also suggest a Singer 201k although it is only a straight stitch, it is a workhorse, and can usually be picked up quite cheaply. Lots of the older Singers would be suitable.
Jessie