I have straps from 12 or 14 different makers at the moment and I think one of my favorite straps is one made by L’Invitta Legione
http://www.linvittalegione.com/watch-straps Its kind of in that sweet spot where it’s really good quaility for a really reasonable price. Even amongst ones that I paid twice as much for. It’s good quality, soft, flexible. I love the feel and way it bends. There are some I’ve tried that seem a little better but there’s a big difference in price. Or some that are less expensive but sometimes the quality drops off.
When looking for a strap though, the deciding factor for me is generally the look that I’m going for. I end up with one strap over another because they have a leather I want, or a style I want or some other differentiating factor. For that strap.