Hi ssnyder! This question has been asked many times before, but will no doubt provoke some replies!
The Queen may be the strongest piece, but personally I have a liking for bishops at the expense of knights. This is probably a defect in my attitiude which I should eradicate, since knights can be excellent pieces, especially in closed positions.
I tend to be a little careless with my knights as well SonofPearl. It may be considered as a weakness by some people, but the knights are great for baiting your opponents king into doing something they've been trying to avoid the entire game.
the queen when i first started playing of course like everyone else....butt now
knights
rooks
Hmmm...if I were to guess what kind of person you are, quny, would I be right to say you like a good challenge?
My favorite chess piece is the Queen.
I think I'd have to go with the pawn. No other piece is so vital in both the opening and endgame.
Just moving or sacrificing a few totally changes the nature of the game, but without the danger of sacrificing minor or major pieces for the initiative.
Besides, if you like queens, for example, pawns are the only way to have more of them. 
the f2 pawn!
The king!
The pawns! For a positional player like me, the pawns are the most important part of the game. Or should i say: The pawns are the soul of chess?
I like the Elephant in Seirawan chess. It has the movement of a knight and a rook.
Either Courier or Chancellor or Grasshopper.
The knight I like most
I like the rook. It seems so tall and intimidating on the board, the gate keeper of the back ranks.
Of course everyone would love to have an army of queens. A better way to phrase the question is, in proportion to its perceived value, which is your favorite?
For me, it's probably actually the pawn. I'm a big fan of rooks as well.
People dont you understand!
All pieces play a major role in the game!!!
You have a great point Mani_B, and I was hoping someone would put that. But although all pieces play an important part in the game, no one can help themselves from leaning towards a piece they use more often than others, or a piece that has proved more useful in your games.
Allright, everybody. I'd like to hear what your favorite chess piece is. My personal favorite is the Queen, as I'm sure most of yours will be. Feel free to write down any number.
Thanks,
ssnyder