I am also a TKD student that has never been formally trained in any weapons. I have dabbled in the Bo and Escrima sticks, though, and enjoyed both very much. As far as practicality goes, my favorite would be the Escrima, for the same reasons someone else has already listed on there that it's the easiest to be translated to a real-life situation. Generally speaking, though, I would love to learn how to use the Katana. It is a truely beautiful weapon to me.... But I would have to insist on using the Highlander sword....the one from the series, mind you, used by Adrian Paul, not the one from the movie, used by Christopher Lambert.