some good answers up there, hehe Mutt got 4 votes and it hasn't even shipped yet!

For me it is Dog Father.

Because I have used it the most, chopped/batoned all kinds of wood, just abused it from day one. I have bonded with it. I know what it can do. And when i hold it, feel its reassuring heft, see all the character marks i've put on the coating, and its gleaming edge telling me it's ready for much more!

..Dog Father is the Ultimate ScrapYard knife to me!