Up until recently I think it was truly a toss-up between my ZDP-189 Burgundy Caly Jr. and my original C-44 Dyad as far as being the EDC I've carried and used the most over the years. But now I think I can say with 100% honesty that my M390 Military has now become my most used Spyderco EDC ever.
Even though I like the overall design of the C-60 Ayoob from an ergonomic design aspect>> I've still used my M390 Military far more than I ever used all my C-60 Ayoobs put together.
Now as far as my Spyderedged companion blades goes that's going to be a tough one. But probably the vote would fairly go to my G-10 Harpy which got stolen from me
Because I carried it almost a full 8 years before it got lifted from me
And I so much want to see a new G-10 Harpy Sprint Run at some point. But next to that one I would say it is my old Spyderedged ATS-55 stainless handled RESCUE because I have sure had it in my pocket a lot too.