For me, there are only two straps, that work:
- original Leica strap with removed rubber pad - I am choking by the price, you have to pay - here it costs slightly less at 22 GBP (I bought a batch last time in Hong Kong for 260 HKD each).
- the Nikon slim camera strap (I can't remember the name) - it is mighty cheap (about 8 EUR), is similarly shaped to the thin original Leica strap (this is not a wide SLR strap, but more targeted to smaller cameras), has no brand name - just plain black with a black soft, very thin leather pad sewed on for the neck, and feels a bit softer and nicer, than the Leica strap.
It has only one downside - you have to find some triangular attachment rings, if you don't like the cheapo keyring solution like me OR: you could reuse your original Leica quick release ends with the cheap but very nice Nikon strap.