Although I have multiple straps, including a Russian variant (fake) on the Black Rapid, I keep going back to my old tried and true Domke 1" khaki straps without the swivels (I hate that much metal hanging around my cameras and lenses). The woven-in rubber strips absolutely keep the strap on my shoulder, the strap is flexible enough to quickly wrap around my wrist for hand carrying, and wide enough to be fairly comfortable on my shoulder, unless I am carrying some really heavy gear, in which case I'll pop on a wider shoulder pad.
The strap is simplicity itself: 1" cotton canvas with woven rubber strips, connecting to 1/4" nylon straps fastened with adjustable plastic buckles and a couple of keepers for the loose ends, and the last ones I bought were, IIRC, less than $15. I still use one or two that are over 20 years old, and still functioning. The nylon straps are just a bit frayed, and the canvas just a touch faded, but they look good alongside my 30+ year old Billingham bag.