Fixed Knife, Folding Knife, Whatever if You Had One Choice on a Knife (not a sword)....

[SKB]

If I had to pick only one........ anything with a blade long enough and well made enough I could put it all the way through someone! A bonecrusher!!! Id I had to pick only one.

 

[KenpoTex]

Large blades: a Bagwell bowie, Keating Crossada, or something similar...

Small blades (IOW, something I would actually have with me): Kasper/Polkowski Companion, ShivWorks Disciple, or something from Ken Brock or Mark Goldsworthy

 

[Baphomet]

I would probably choose a Strider HS karambit for both utility and SD (I've held one once, but haven't owned one yet ). My EDC rotation is a bit more complex.