Ha! I'd drink Zachs' stuff... There's absinthe here as well, although it's illegal, and I'm not sure if any of the wormwood-y stuff is available.

I'm with sivat here (whatz a funny new feeling... mmmm). AFAIK, and that's pretty certain, the wormwood is what makes it a hallucinogenic drug instead of a liquor, and the good old absinthe of 18xx had a fair amount of whatever there is in wormwood. Most of it may have been crap liquor as well, but that's beside the point. The reason why absinthe is illegal in most countries now is the wormwood. It has some massively brutal health implications, as in "kills you fair and square". I'd have to ask my medical student buddy again to say exactly what, but it's in a different leage from bad booze. Way worse. It may make the stuff more addictive, too (although alcohol is pretty high on the addictiveness ladder in and on itself).
I guess it's a matter of dosage... If the percentage of the drug ingredient is low, then the alcohol knocks you out before you could drink enough to get really high and destroy all your internal organs.

I'm too lazy to look up the names, but a good couple of Romantic poets and painters lived in a dreamworld of absinthe visions... that stuff was pretty intense, it would seem.