What is the worst beer in existence?

a toss-up between Stella, Heineken and Corona

Literally 3 of my 4 or 5 favourite beers...

I have to agree with those who posted Miller Lite...

Steel Reserve as well, I have made some pretty terrible choices after drinking 2-3 of those tall cans... /shiver

Wow isn't it shocking that someone who would chose a SS Nazi (tiger??) as there image is going to troll. Lets check out his profile shall we? Favorite books Mein Kampf. Super. What games does this fine citizen prefer? Oh "Murder Simulations". Oh and finally interests, "Nazis n' Furries n' Shit". Ahhh the image makes sense now! I had no idea neo-Nazi-Furries were a thing. Thank you for broadening our horizons Pawmaniac. 

Definitely over-rated and over marketed. But fat from the worst...

I'm sorry but what you just said fails a sanity check. Most big brands produce cans, even most very expensive micro breweries produce cans, if you don't drink anything available in a can you basically don't drink beer. Its not really a question of how fussy you are its just for manufactures there is little difference in profits per milliliter so most will bottle and produce cans to try to reach as much of the market as possible.

An interesting aside is the color of glass chosen, you actually need different perspectives for clear and green glass than for brown glass and cans due to the availability of certain spectrum of light to algae. This preservative can adversely effect flavor so many breweries have gone back to cans or dark brown bottles.

Cans also typically last longer than bottles due the a better seal on the lid and are less likely to explode when live yeast is still present due to higher tolerable deformation. These factors have lead to its strong utilization including by micro manufactures, one thing I have discovered however is due to the thin walls can are more prone to failure from friction during shipping, I have seen an entire case of empty cans as a result of this failure on a particularly bad road, so place cardboard or similar between cans if you intent to ship them via load distance road transport.

As far as bad beers go there isn't the massive selection of bad brands locally due to high taxes thus fairly high price floors, so I guess I can just list the beer than build Australia, XXXX, its flavorless cold and tastes like a sewer if it warms up, yet somehow manages to be on of the best sellers at any pub, bottle-store or restaurant. Also its more expensive than some honestly quite decent beers like Oettinger Pils, shows how uncommon taste really is in this world.

Laker Lager 

Odd I used to get Heineken (about 6 years ago) and it wasn't bad, however i stopped as the price begain to rise. Clearly quality has fallen too, a shame.

I've always laughed at the way Carling is different in every country where its sold, south Africa (where it originates from) has a stronger version while Brittan has a darker weaker version and Canada has a preservative free larger not based on the product anywhere else. Having said that like tiger beer, Carling is always the generic drinkable, but not fantastic beer available everywhere, so I'm not surprised it'd be your pick if you don't drink beer much.

3 worst common expensive beers? Maybe, but all are perfectly drinkable, especially the Corona if its a 40+ degree C day and its served at 4 degrees with a slice of lime in the neck.

VB, XXXX and Carlton Draught are all worse beers for not all that much cheaper, and you can do even worse than that.

Slots Classic This must be the worst ever. Leaves a film of oil on your tongue with a chemical after taste. Comes in bulk from Germany to Sweden by alcohol smugglers who want to sell it to teens.

non alcoholic beer

Terrible.....

Or this...

 

Cat piss in a bottle.

Potosina from Potosi, Bolivia. Worst beer I've ever tasted.
Other beers from Bolivia are better, but nothing to write home about.

This: 

Definitely the Pokal Pilsner. It is like $0.50 here in Denmark, and is the cheapest beer (usually). It just as bad as Budweiser IMO.

Holy sh**.  That looks horrible.

I am a big fan of Leffe Vieille Cuvée, I have not tried the others but I hear they vary quite a bit.

Miller Genuine Draft.