I've always been fond of any of the dancing taunts, but the ones I favor the most are the Conga (because my first exposure to Team Fortress 2 involved me seeing a video of those massive conga lines around the time the taunt was first released, resulting in me being fascinated by it) and Mannrobics because I enjoy the movements and the recurring music that plays for the duration of the taunt. Try playing different songs to the taunt and see which ones match with it.