The Mad Queen
Memento Mori. Unus Anus
Any universe that has something that comes close to fragmentation grenades, flashbangs, gas grenades or gas attacks, poison darts, something that could be used a flamethrower etc and common sense has a chance. Get close with a flamethrower and most have almost nothing to defend themselves with.
The only thing that can see or harm a stand directly is another stand... And if you can't see something, you can't know it is there. And with Force users, it can be as obvious as they allow it to be. Such as a cold feeling by Dark Siders which can be strong enough to be felt by and sometimes even corrupt (though these occassion are rare and require prolonged exposure) non-Force sensitives.
While the only thing that can directly harm a Stand is another Stand, there is only so much they can actually block to protect their user. You fire a hail of bullets or even arrows at a Stand at the very least a good number of bullets and/or arrows will fly off and hit the user, thus damaging the Stand.
You don't have a Stand? Fine, take down the Stand by taking down the user. Something many non-Stand users are capable of.
Also, just because you can't see something dosen't mean you can't defend yourself from it.
Also, any universe that has access to those things could be used against a Stand User. Stands require concentration to be used effectivley. You damage that concenration with something like a flashbang grenade and you've made the Stand User vunerable.