Ahh finally, there's a way for me to contribute to this great forum!
If you are looking for exotic leather (gator/croc, ostrich, stingray, chicken leg, "regular" leather like calf, etc) I highly recommend Hoang who owns HoangDidDatStraps -
http://tuantom.com.
His FaceBook is a much better way to peruse his work and see what he's capable of (warning: this is a time-suck, he has tons of pictures for you to ogle at):
https://www.facebook.com/pg/vietnamhandcraftedleather/photos/?ref=page_internal
https://www.facebook.com/pg/vietnamhandcraftedleather/photos/?tab=album&album_id=2434524673353482
Very high quality straps for the price, highly customizable for odd lug sizes and length etc, and the customer experience is second to none. He's a very easy guy to order from and super responsive (just send him a FB message), I changed up my order several times because I made a mistake on the lug width of an incoming watch and he's very flexible (this was my fault so of course, try to get it right the first time). Probably the biggest downside is the wait-time because he has a wait list (he's popular) and he's located in Vietnam - you're not going to get the straps the next day so there's an element of patience that's required.
Here's the incredible variety in just Ostrich leather alone that Hoang has, pretty much every color under the rainbow! Another downside to this - deciding what you want to buy!