Klim
These guys ^^^. Check their 'deals' section for non-current gloves (as well as other items) at better-than-regular prices.
I'm tall with long fingers, typically wear a 2x glove. But before ordering gloves from Klim, I actually measured my hand -- according to their glove sizing chart, I should wear their size large.
I didn't believe 'large' would work but ordered a couple pair of size large anyway, thinking, "Large? No way. When the large gloves arrive, I'll try them on, find them too small and exchange them for XLs or 2XLs."
Nope.
Klim size large gloves fit my long-fingered hands, um, like a glove.
This is a huge departure from every other (mountain bike specific) glove I've ever used.
Excellent quality construction, too. I not only wear Klim gloves, I've got other apparel by Klim, too -- moto pants, jersey, socks, even one of their casual shirts. Klim's stuff is of the highest order when it comes to materials & construction.
=sParty