I like VLC cause it's light too
Ok, I admit it, it's kinda fun to see old threads revived. I prefer WMP. I know where the options are, it works well. There is something to be said for spending only a couple seconds adjusting, and then enjoying the video.
However, some codecs do not seem to play correctly on WMP for me. VLC is my alternative for this.
Also, I will mention that Divx Player has been quite buggy for me lately. I install it for the codec, not the player.