PM2 for sure (Everyone should have one), but having said that, the Domino is very close in size and ergonomics to the Manix2 and should also warrant a look, especially if you want to try a framelock. It's closer in size and ergos than the Sage 2, and I think the longevity is going to be better due to the overstop travel bar/steel lockbar interface piece. Either way though, you can't go wrong.