I know barely anything about Ataris. I started with the NES when I was 3 and pretty much went from there, aside from playing an Atari maybe a couple random times in my life. So, I'd like to get 1, but I'm not sure what to get.

First, there seem to be a ton of versions of the 2600, is there 1 in particular that's considered to be the best? Were any features removed from any of them?

According to Wikipedia, the 5200 wasn't backwards compatible, but then an adapter was released to play 2600 games. Is that adapter expensive/rare? And are all 2600 games supported by it?

Also from Wiki, the 7800 can play almost all 2600 games. Are any of the better games not supported?

What kind of outputs do these systems have? Am I looking at mainly RF for all of them, or do they have composite as well?

Which system has the best controller?

Most of the games seem to be for the 2600, the 5200 and 7800 have very small libraries, are there even any worthwhile games in those small libraries?

I guess those are the only specific questions I have, but I'd appreciate any information/suggestions/etc you think would be helpful to an Atari noob,