Falkniven makes several small folders in SGPS @ rc 62 It's a nice powder steel that takes fine, sharp edges. Several people who I trust have gotten pretty low scores on wear resistance on their tests. Despite that it is a premium powder steel that will take very fine edges.
Rockstead ZDP 189 ( often laminated with ATS 34), and YXR7, a HSS alloy ( non stainless). These are very expensive, well made knives that need special sharpening equipment and technique. It's got the best out of the box edge you will find on a production folder. ZDP, and YXR7 are both run well into the RC 60's, and are both wear resistant. I have no experience with YXR7.
Strider SNG production and Dwyer customs in steels like S110V, and really highly alloyed specialty steels like Rex 20 ( M62), and even Rex 121. Some of these ( rex 121) I have no experience with. Pretty expensive for the Dwyer customs of course.
Fantoni folder in S125V. Very, very rare folder specially imported by forumite Hardheart. Remains to this day the only production S125V folder I'm aware of. Ran @ rc 62.5 and very well built by Fantoni, which is no surprise coming from them. Thanks Hardheart!