I had a Zima once at a picnic. It tasted sort of like what beer would taste like if it didn’t taste like anything.
Coors Light?
Naxos citron. I had bought it entirely on the basis of considering it a tribute to Mr. Scott. (“It’s green.”)
This was during a summer mostly spent in pursuit of the cheapest wine in Europe that was still drinkable (somewhere in Spain, approximately $1US/liter).
This Naxos citron was another thing entirely, and neither the Aussie nor the sturdy English midlands guy I was hanging out with would have anything to do with it, either. We wound up pouring it down a toilet in Naples.
I had been sitting here trying to remember what it was called and what exactly was wrong with it. This triggered my memory, thanks.
Ratzeputz. It’s like licking an ashtray and washing it down with gasoline. With urine in it.
It was a right of passage where I was stationed first in Germany. One shot of it. No prob, says I.
I wanted to die. I don’t think I drank alcohol for a month. Which is a crime in Germany.
Some say it has the essence of ginger.
Not in my universe.
While in college, a friend and I threw together a primitive kitchen still to distill some party-leftover Budweiser that we both had turned our noses up at. The still worked, but, trust me, raw, concentrated Budweiser is not better than the regular stuff.
Some friends brought something seriously nasty back from Korea once. I don’t remember what it was called. It was just awful but very potent. We kept it for ages thinking we could use it as a mixer but it was so bad it ruined everything it was mixed with
I find Underberg to be exceptionally vile tasting (Underberg - Wikipedia), but it works amazingly well as a digestif. Someone once wrote that it sets off a bomb in your stomach that frees you from the agony of over-indulging. So the trick is to hold the bottle between your teeth, throw your head back and get it into your stomach without it touching your tastebuds…
Worst drink I ever mixed (but didn’t drink myself) was Pernod & Aquavit. Some guys used dice to decide which numbers on the menu they wanted to try together. After this concoction, they went back to using common sense.
As a straight out of the bottle drink it is hard to beat Ouzo or Green Chartreuse. Both are rank.
However, the worst drink I ever had was what is called (charmingly) in the US an “Irish car bomb”. It is a shot of Jameson and Bailey’s dropped into half a pint of Guinness. I don’t know whose idea it was to combine three palatable enough drinks into that abomination but they should probably be at some UN tribunal in the Hague for crimes against humanity.
Actually thinking about it now the car bomb wasn’t even the worst drink I’ve ever had. Aged about 17 I was broke so scabbed a few drops of everybody’s drink at a party. The rocket fuel was just about drinkable until I added some Bailey’s and the whole concoction congealed. I am sad to say I drank it anyway. Bleh.
I like rauchbier. Triumph brewpub in New Hope PA had a batch made up a few months back. Very interesting.
I tend to be not very adventurous with hard liquors (because I am a pathologically cheap bastard and booze is expensive) so I do not have many stories about trying something nasty.
However, I did not like Sam Adams’ Maple Pecan Porter. Much too sweet for my taste. I am also not a big fan of any of the pumpkin ales that are foisted on us every Fall. Beer should taste like beer, not like pie.
God, I swallowed a pretty sizable cigarette butt that way… Could barely keep my stomach intact. Probably should have puked it out, but I loath puking.
Once upon a time, around the giftsmas holidays, someone accidentally poured a couple shots worth of Crown Royal into a mug of milk on the table. As the night wore on, the milk separated more and more. By the end of the night, when we had run out of liquor, a friend and I began coercing ourselves to drink it. (Hey, I was 17.) We did. It was absolutely awful, like gritty Laban or Baltic yogurt on top of whisky.
Mezcal. Specifically Gusano Rojo Mezcal. I’m no big fan of tequila to begin with, but this #!& should be illegal. Apparently it's made to fool gullible and cheap tourists into thinking they're buying Tequila. Vile. It tasted like some Mexican dude drank nothing but tequila for four days, and then pissed into a half jug of paint thinner. What makes it worse is it's weak as #!&, so if one does decide to choke it down, it takes quite a bit to hit that “so drunk I don’t care, just give me more alcohol” stage. Smells awful to boot.
Two entries. One was a college “right-of-passage” kind of drink that was given to me by my Freshman dorm RA. It was called a Prairie Fire, and wiki actually says that it is a thing.http://en.wikipedia.org/wiki/Prairie_Fire_(mixed_drink). The one I had was a “Mexican Prairie Fire”, tequila + tobasco sauce. Prairie Fire + Tony = instant vomit.
The second I had while deployed to Okinawa. Habu-Sake. A dead Habu snake pickled in a big jar of Japanese Sake. Habu snake venom creates an interesting, long-lasting type of headache that ws unique to this Sailor’s experience…
I’ve had many drinks I hated the first taste of, but vowed I’d finish. Then I ordered another. A recent craft IPA aged on orange peels and served cask style (but too warm) is one example. Carton Panzanella, a tomato/onion/cucumber salad beer has grown on me.
But, wondering about Thorogood, I once ordered a shot of bourbon, a shot of scotch, and a draft beer. I drank them in that order and it was awful. I like bourbon. I like scotch. I like beer. But in that order, back to back, it was awful.
God help me, my wife LOVES Malort.
Jagermeister. I tasted it once and wanted to vomit.
A Greek restaurant that my wife and I go to had a drink special one night - Greek margaritas, which were made with ouzo instead of tequila. It tasted like I was drinking a Ny-Quil margarita.
That sounds absolutely vile. 
I’m one of those weak-charactered creampuffs who enjoy fruity sweet cocktails, so this probably won’t hold a candle to what’s been posted already (and frankly, some of your descriptions have made me feel sick), but the worst-tasting alcoholic drink I’ve ever tasted is Fernet Branca. Legend has it that it cures cholera, and I can believe why someone would think so.
That sounds like unsweetened Jagermeister. I bet it was awful. 
Goldschläger, any kind of Schnapps, Wild Turkey, Southern Comfort, chocolate wine, Moscato…
They are not friends of mine
I will not drink them like I did that one bad time
I’d rather kiss boy cows, poot in the night
Lose my pants to a gar, have a water balloon fight
A (now sadly closed) Greek restaurant here offered a Black Cretan - ouzo and Kahlua. It was actually quite good, at least to me, and was always my go-to drink there.
As far as the worst, I like to take advantage of our local supermarket’s “make your own six-pack” deal, with all their various single bottle craft and specialty beers. One day I saw something called a smoke beer. It even had a little award mark on the bottle saying it won best smoke beer in some contest.
Well … it tasted like pure smoke. The artwork of the brick smokestack on the bottle accurately depicted the taste of this beer. I could handle only two swallows before I dumped the rest of the bottle. Ack.