If you've been looking for something a bit more luxurious than Apple's own in-house strap options, you could goto Hermes or try something a bit more unique. Hadoro Paris has introduces a line of alligator leather straps and whether you're sporting the stainless steel or rose gold/gold options, they've got a strap for you and even the hardware to match. The straps come in a variety of colors and if you need the matching hardware for your Edition watch, the gold and rose gold variants are also made from solid gold.
Shinola is bringing its leather watch straps to the Apple Watch
The straps are available for both the 38/40mm and 42/44mm models.