Most fun Atari games I'd say fall into this. It's hard for me to call a game terrible if it's fun, that normally makes it a good game. So maybe we should change it to more of "Games you think are under rated" or something like that.
I like Haunted House on 2600. A lot of people think it's a bad game, but to me, it's one of the few 2600 games where you get to do stuff. Most other games, same screen, over and over, just shooting or catching the same stuff, over and over. No exploring, nothing.
And as I said on the other thread, ET. 90% of people bash the game without even knowing the goal: Find the three phone pieces, find the spot to summon the ship, and find the landing spot in the forest. Many times you can beat a level by lowering yourself (NOT FALLING!) into 3 pits. You need to find the ?s spots, most of the time all 4 pit screens have them, and use it to locate the parts. At the very least, you have 2-3 that rule out what screens there are no pieces on. then you enter a pit, levitate soon as you enter, and lower yourself if there's a part, otherwise, exit the pit and try another one.
Blue Print is another one I hear people bash, and they don't seem to understand it. https://www.youtube.com/watch?v=5EMEsWaFtM8 was one where the guy talked about the gun part. He didn't know you need to press up to raise the gun's power, so he was shooting at it with the slowest speed, the hardest way to do it, and for most points. Great thing was, his own video, at 9:30, shows a clip of the instruction manual that shows how to do that.
A lot of Atari games are like that. People don't know the tricks to play them, and think they suck. Yet you have games like Yars Revenge, people know generally how to make the cannon show by eating or touching the base, but if you didn't, that would be a very frustrating game.