Like others, I'm not gonna make a single determination for one metal-handled knife that is my favorite. I'll go for a group.
First, although I don't own one, I like the Sebenza. I also am going to love the Spyderco ATR when it comes out (though its expected price point may put it out of my reach).
Of the knives that I own, I am now very fond of my Kershaw Vapor and Vapor II. (I just finished touching-up the factory edge that came on the Vapor II. It's ready for EDC now and will see good use.)
I also love my Spyderco Copilot (plain edge). I wish I had a second one. (I love having backups for my favorites, to take the worry away from losing or ruining one.)
---Jeffrey