Lemme see if I can give it a go...
Caffeine
nicotine (14, never got to be a regular user!)
Alcohol (19)
Weed (tried at 15-16, got high first at 19, fairly regular user ages 19-20)
Mushrooms (21)
Vicodin, recreationally (21)
GHB (21)
DXM (21)
nitrous (22)
ether (22)
ephedrine, at recreational levels (22)
kiddie speed, dexedrine (22)
5-meo-dipt (22)
cocaine (22, regular user now: 3 or 4 out of 7 days/week)
meth (hi-potency "glass") (22)
codeine (recreationally, 22)
ketamine (22)
morphine, insufflated (22)
Still on the list of things I plan to try: PCP, H, Peyote
Things I don't plan to try: MDMA, LSD
I like the more predictable effects of uppers, downers, and dissociatives, so I stay away from the funny stuff.