I have a 2600. I also have a picture of me at 7 months old, at Christmas, sitting next to our new 2600 VCS and 11 games. This was back in 1984. Of course, I wasn't into it at the time, but as I grew older I became attached to that system. I fought to keep it a few years ago, when my parents waned to get rid of it. I have since expanded the library. I can't remeber them all, but here's what I can remember.
Pac Man (Sears and Atari labels)
Ms Pac Man (red)
Jr Pac Man
Death Trap (I am so glad my mom and dad got this one after looking at the list)
Star Trek
Star Raiders
Combat
Pong (Sears typing label)
Basketball (sears label)
Football (sears)
ET
Raiders of the Lost Ark
Tutankham
Spider Fighter
Astroblast (manual, but no cart. been missing for years)
Journey Escape
Dark Cavern
Armor Ambush
Pole Position (most common label)
Mouse Trap
And that's all I can remember for now. My rarest game is Death Trap, and if you have not ever played it, it is a fun game, I think. I have the number pad (I think it's for the 5200 though, not sure), some paddles that say "racing" on them, and the common "Gemstik" controllers. I also have an arcade-like joystick, with the button on the top of the stick intead of off to the side.