Drugs. MDMA is my favourite readily obtainable substance, shrooms are fun and not all that hard to grow (allegedly.) Also weed obviously but I don't really consider that a worthwhile drug by itself, unless you get quality homegrown sativa and bong it, at which point it can be very nice with closed-eye visuals comparable to shrooms.

Also done coke (don't like it), meth (bleh), amphetamine (MOAR PLZ), salvia (believe the hype, insane at high doses) and codeine / hydrocodone (don't really affect me, presumably I have shitty CYP2D6.)