Light-as-baton sounds great in theory, but in practice is kinda sucks. A real cop carries and uses a REAL baton, like the PR-24 I keep in my truck, or an extendible all-steel ASP. Most bozos have very hard heads and you risk not only damaging the light, but losing the illumination which helps you keep track of your assailants.
Don't even consider using or carrying a knife unless you're a martial artist. Knife fights are nasty and bloody affairs, and generally nobody wins. First person to pass out from blood loss loses. I've seen the results firsthand and it isn't pleasant.
Here in TX we allow the civilized practice of licensed concealed handgun carry. I normally don't feel the need to shoot drunks or the typical bozos I run into, so rely on Fox 5.2 or Freeze +P sprays, both of which are law-enforcement formulations. A couple of squirts in the face takes the fight of just about anyone except a person jacked up on PCP.
As a backup, consider a handheld stunner, 500KV level, which is about one notch less than being tazed.
Neither of the above will get you sued or locked up, unless you live in a liberal wacko state, and although painful at the time, cause no real damage.
[sarcasm mode ON]
Now if you live in a liberal wacko state, it is better to go ahead and allow yourself to be killed or maimed. After all, that poor and undoubtedly misunderstood felon has rights, and you wouldn't want to abuse them by actually fighting back. After all, he might get injured, and thereby institute a lawsuit against your estate. In this case, it's better just to run away!
[sarcasm mode OFF]
Barring the use of lites as bludgeons, or any other weapons, I recommend a BIG dog!
Bets Wishes,
Ron