Over-rated: Weed, DXM, coke, Rivotril/Klonopin (Clonazepam), Xanax (Alprazolam), MDMA and alcohol
Under-rated: Nitrous, MDA, most psychedelics, Dexedrine, Valium (*specifically* Valium, why people prefer Xanax when it's less euphoric than diazepam is beyond me), Mogadon (Nitrazepam), Midazolam