A Spyderco Tenacious. My brother gave one to me as a gift, after that it was all down(up?) hill. Before that Spydie I had a bunch of Kershaw's, Gerbers, other random knives that I carried day to day, but once I got that Tenacious I really found my groove. So obviously the next step was to join a forum that was full of other knife fanatics to converse with and learn more about my newfound love. Gotta love the Internet!