This is what the following drugs do to you:
Marijuana -- Brings things that you normally don't notice into uncomfortably sharp focus. Makes the commonplace seem bizarre and alien. Sensory overload is very possible while on this drug, to the point where everything starts to feel absurd after awhile. Dries the hell out of your eyes and mouth. If you tend to suppress a lot of your fears and anxieties, it might bring them directly to the surface. Makes every action require a thousand times more effort than it normally would. Sometimes paralyzes thought processes and glues your mouth shut.
Alcohol -- Makes you either puke or pass out. Up until you do one of those things, makes you think you're having more fun than you've ever had in your life. But you're not -- you're just exercising poor judgement.
Cigarettes -- Make you feel like the coolest person who's ever lived. Then if you ever stop smoking, it makes you hate everything in the world.
LSD -- Brings out colors and shapes that normally don't exist. Makes you love everything in the world. Makes walls vibrate. Causes sensory confusion (sounds have colors and stuff). Makes you stay up all night smoking and talking with other people who are also on LSD. Makes all music awesome, even if it actually sucks.
MDMA -- Makes you love everything in the world. Makes physical sensations feel a thousand times more intense. Makes you sweat buckets even if you're not doing anything. Makes strobe lights seem like the coolest thing in the world. Absolutely destroys thought processes.
Meth -- Makes you feel superior to everyone and everything that has ever existed. After that goes away, makes you want more meth.
Crack -- After five minutes, makes you want more crack more than you've ever wanted anything.