powder heroin duh!!! god I would be so happy...I know plenty of junkies I could sell it to also, so I would be eternally high + rich...no more student loans or government robbing my paycheck and then giving me a shitty tax refund...
pure MDMA would be a close second, but you cant be on it all the time and functioning normally, and I hate the comedown (unless I have dope, which is the cure for all comedowns!)