Straps are one of those accessories that seem to accumulate. Considering what they do and how much you need and use them they can become very personal. Although a really good one may seem expensive, if you are using it on your favorite Leica or other camera its a minor investment.
I still have and use a custom made strap given to me by my sister many years ago. Designed after the old Leica strap its still in great condition being made with the best leather, tooled edge impression and horsehair stitching replacing any metal in the design. On my R-D1 I've got a double thick Artisan & Artist ACAM-282 leather strap, nicely made and very strong - don't have to worry about this strap failing. Just picked up one of Artisan & Artist's Japanese traditional 'Kumihimo' braided silk cord straps a couple weeks ago, very soft on the hand and flexible, maybe the strongest strap that's non-metal ever made, camera lugs will give out before this strap does! Thought I'd stick with an all Japanese theme for my new Nikon SP 🙂
In general I don't go for shoulder pads, metal or plastic adjustment buckles these days as I tend to wrap the strap around the lens for storage and to protect the lens when its in the bag.