I know you mean this in jest, but if you use a taser then you can't hang around for the police to show up if the attacker is determined to do you harm. A tazer causes a great deal of pain and disorientation while it is actively sending juice into the attacker. As soon as you let off on the trigger or the probes fall out, the attacker can quickly recover, come after you again and will likely be very angry at you. Because of this aspect of it, I am not a fan of tasers at all.

Pepper spray stays on the attacker, paints them red so they are easy to identify, and blinds them for up to 15 minutes. There is no perfect defense but pepper spray is one of the better ones IMO.