Depends upon the situation you find yourself in, and your reason to carry either or all of them.
Taser-My Dept. does not carry them so I can't give you a better answer than this; I have seen them utilized and they do in fact work. However for which type, model number I am at a loss. We used to carry Nova stun guns but they are ineffective against EDP's so we dropped them.
Baton-I still carry a nightstick and prefer it to the ASP collapsable. It's just my preference since I was raised on the nightstick and issued an ASP a few years ago. The ASP is a nice weapon, easily concealed (if that is mission essential), and holds up well during deployment (ie will not bend or break). If I had to find something bad to say about the ASP it would be it's tendancy to collapse during use if not extended forcefully enough. Moreover once extended you need to strike it against a hard surface (wall, street, pavement) to reholster it (not a quiet process).
Pepper spray-We carry Punch III which is a Cayene pepper base. It's great stuff and works as advertised. You will have to choose where/how to deploy it as pepper spray is much like any gas-once it's used the immediate area is contaminated. Experience: I have been sprayed by more partners using this stuff than I care to mention. If your tango wants to fight, and you have to go hands on, you and anyone else assisting WILL be affected by the spray. The effect is much like your trip through the CS chamber-all the snot and sting, not complete incapacitation but enough to make you move out of the area pronto. Also the spray gets on everything; clothing, skin, hair, equipment-all of which will give you that warm fuzzy remembrance hours/days later when you touch the stuff again and rub your eyes or nose. Be advised pepper spray's effect (in my experience anyway) is severely hampered by a cold weather enviornment! The desired incapacitation will only come to fruition when the subject is returned to a warm air area (see vehicle/house/hospital etc).
If your wish is to have the pepper spray to contaminate an area for the expressed purpose of slowing a pursuer during an E&E I could not imagine a better product!
Hope this helped.