Originally known as the Atari VCS, and if you knew that we'd tell you to get out more if it wasn't pointless. And too late.
An MOS 6507 CPU with 128 bytes of RAM (yes, that is bytes, and yes, that does mean it took more RAM to display this sentence than Atari games.) Most games could only manage about five moving objects rendered in six different colors. That's less powerful hardware than a bag of jellybeans.
The Atari 10400
An entire generation of children spent hours either playing Atari or wishing they could, thereby proving pretty much everything anyone says about us gamers. We're not saying it was made by the sorts of people who think "micro-processor" was a word for Asian factory workers, but early models had wooden paneling. Of course, since its primary competitor, the Fairchild Channel F, was designed specifically to look like an 8-track player, nobody seemed to mind.
Atari's Pac-man has remained the worst screwing of a sure thing since someone used a winning lottery ticket as a wankrag. Atari took what was the most popular arcade license to date and gave one man, Todd Frye, six weeks to destroy it. He succeeded beyond their wildest nightmares.
From the decision that player didn't really need to see the ghosts all the time (making them flicker at a rate which accelerated from zero to migraine in ten seconds), to changing the shape of the pellets from dots to dashes (possibly the only Morse Code translation error in the history of gaming), not one aspect of the title went un-ruined. What was intended to be the best-selling game of the industry's history was instead half of the reason why it crashed.
Freeway (1981) [from Bloody Human Freeway]
BEHOLD THE GORE!
Bloody Human Freeway wanted to be the Mortal Kombat of its day, having a human running across a motorway but - just in case that sounds interesting - you could only move in one dimension. And - just in case you've had a sledgehammer rammed into your skull and that still sounds interesting - Activision wimped out of the 27 pixels of blood and in an insightful self-parody turned the players into cowardly chickens which automatically jumped away from danger
It didn't help that the game design turned it into a "which way is up?" competition. Hold the joystick that way and you win.
Strawberry Shortcake's Musical Match-Ups
Guaranteed Bad Game Strategy #2, "Let's make a game for girls!" forced players to rearrange clothes in order to hear the 2600 play music. You know, because girls like music.
The game that came with the Atari 2600 and boasted an amazing 27 games in one, though that's by "Combat logic" where changing your socks doubles your wardrobe and kissing your girlfriend while wearing a hat means she's cheating on you. The 27 different games were more like different "levels" of the same game, and even that sometimes meant the same level in different colors.
Two of Combat's different "games" (Note: still more change than the average Madden title)
No jokes. We'd still play this forever, without question.
Defaulted to one of the best games ever because it was a working Pac-Man, AND you were chased by aliens instead of ghosts, DOUBLE-AND Ripley could eat the chest-bursters when she got the glowing pill aka "A scene which would give Giger nightmares and Freud a boner."
One of the few popular educational titles. It provided perfect training for life: you spend all your time doing and undoing pointless things simply because someone told you to, one wrong step and you'll ruin everything, and other people will devote themselves to undoing even your thankless task for no other reason than they can.
Making erotic games on the Atari 2600 was like building a fire truck by origami - a terribly damaging decision which should have been identified as stupid before the designer had finished spitting paint flakes to say it. Except third degree burns heal faster than the psychological trauma of masturbating to eight pink pixels. To this day the Japanese can't achieve erection without the women doing something heavily pixilated in public.
Bachelorette Party (1982)
An astonishingly bad breakout game where the blocks are a rainbow of dicks, the ball is a girl, and the paddle is edge-on. And for Breakout fans that last bit is the worst. And the girl exponentially accelerates so that it's actually impossible to play for longer than ten seconds, which is not a problem a regular human will have. The game required a paddle (similar to other erotic games/worst things ever like "Beat 'Em and Eat 'Em), which was tragic: anyone playing this game desperately needed a lot of things, but more Atari 2600 hardware is right at the bottom of the list (after mercy-killing and "A restraining order from the rest of the human race.)
Custer's Revenge (1983)
You might not have expected a Union General to be part of the Worst Thing Ever but here we are. The game's graphics are significantly less sexy than Lego, its rendition of The Last Outpost is the most disrespectful version of the song since Carlos Mencia farted it, and the fact the game can be set for 2-player is the one and only positive argument for "Grenades thrown into enclosed spaces."
People noticed that rapidly cycling the power on and off would generate weird effects in their games. In other words, Atari 2600 games were so bad that children would try to melt their own cartridges just to get them to do something, anything differently. Nowadays things are much more advanced: Microsoft designs its consoles to melt themselves for you.