Well, I dunno. What is the knife for? Whittling tiny wooden camping companions? Stabbing a bear that聮s chasing you on your mountain bike? Performing minor surgery?
Swiss Army Explorer

It聮s safe to say that the handiest all-around knife and tool remains the trusty Swiss Army-style knife, such as the Swiss Army Explorer ($44; www.swissarmy.com). I regard these things as indispensable. True, the knife blade isn聮t fabulous, but it聮s OK for most everyday tasks such as making kindling or cutting cord. And it has useful tools such as a screwdriver, can opener, bottle opener, and so on. So it聮s very handy for the many odd jobs one encounters, such as working on stoves, repairing packs, opening food pouches, and so on. What聮s not to like?
If it聮s really a blade-only knife that you聮re after, then I like folding models with a fairly short blade. Spyderco聮s Delica 4 Lite ($68; spyderco.com) is such a knife, with a compound blade (straight edge and serrated) that folds snugly into a textured nylon handle. It聮s very, very sharp and light. Gerber聮s Armor Serrated Knife ($48; www.gerbergear.com) has a slightly shorter combination blade with a very comfortable handle. Nice knife as well.
You聮ve got your winter gear, now get outside and use it. makes it easy to find nearby slopes just begging for fresh tracks.