I live in a high humidity area and taking care of carbon steels here is a year round challege. For that reason, except for a couple Busse's, I only consider SS.
Mine are all in the newer stainless steels -- 154CM-S30V-S35Vn-M390.
The Benchmade 581 Barrage w/M390 (SS) just became legal to possess in my state. In my experience M390 with a blade hardness of 59-61 is an impressive improvement in SSs relative to edge holding.
I would also include in the high end of SSs Faulkenhevin's proprietary 3G (a powdered and laminated steel with a HRC of 62).