If you're looking for interesting spin-down behaviors, include some tops with ball tips and high centers of mass along these lines...
By sliding the rotor (widest part) toward or away from the tip along the central shaft, you can adjust spin time, self-righting tendency, ability to stand against impacts, precession rate, etc. In the process, you also adjust the sounds a top like this makes on a resonant surface like a glass platter, empty plastic bin, or guitar body. Very entertaining.