Sure, weed obviously is one... what else, let me google that... alright well weed, tobacco (maybe a bit more dull than you were thinking), various sedatives to a greater or lesser extent although maybe that's also a little too dull for you. Obviously most psychedelics are out, stimulants can vary but potentially could be a bit dangerous so I wouldn't really feel comfortable mentioning any specifics. Of course whether ANY other psychoactive drug is a good idea or not is a whole other question... but you have some options I think... obviously depends also on the antipsychotics, which ones are you on?
I found
this thread asking about Seroquel (quetiapine) and entactogens also - essentially says similar to what I just said except that amphetamine and ethylphenidate seem to be mostly OK, at least that's what I gleaned from skimming it briefly.