I'll mention Frogger first because that's the first game I made it to the end and beat. 
I was into Pit Fall, Centipede, Missile Command, Pac Man, Combat, Donkey Kong (which I came close to mastering), Space Invaders, and the 'Real Sports' games they came out with. When you hit a home run in baseball it was the most annoying sound. 
I LOVED Defender in the arcades but the Atari version sucked. I had Yar's Revenge too and was terrible at it. 
I had sooo many games. I can't remember them all. My grandmother had a monthly subscription for games. Kind of like Columbia House. You'd get one game a month for whatever cost it was. Anyway....What is the worst game you played? For me it was Riddle of the Sphinx. I could never figure that out.
I've only played that one more recently on an emu but pretty quickly abandoned it in confusion too. For some 2600 games you really need to read the manual, I guess. Atari pretty much created the video game industry and then almost killed it with a glut of bad games, In terms of bad taste there were some porno games released for the 2600. The most offensive is probably Custer's Revenge, in which you, playing Custer with a raging hard on, must avoid arrows in an attempt to make it across the screen to rape an Indian squaw tied to a post. It's racist, sexist, in poor taste and really not that much fun to play after you get over the "shock" factor.
I'm one of those people who actually bought ET and after falling in a hole repeatedly, promptly returned it. Another game I returned that people now have a lot of nostalgic love for was Adventure. While I liked the concept (which is why I bought it) I thought the execution was lacking, to say the least. I mean, the dragons looked like ducks...DUCKS
Anyway, I'm now aware that it contains the first Easter egg and all but I just couldn't (and still can't) get into it. Games like these were the predecessors of the RPG and, unfortunately, I've yet to find one that really grabs me. I say unfortunately because I know that the people who like them REALLY like them and will often wax poetically about them but I've just never been able to connect. Maybe I'm missing that part of my brain in the way a serial killer is missing empathy? I don't know.
BTW, there is a "fixed" version of the ET ROM out there in which you don't fall in the holes so easily, for anyone who still wants to try playing it.
P.S. Atari did have a great version of Frogger. It was almost identical looking to the arcade but it was the one made by Parker Bros. and not Atari though.
