I still have my Atari 2600, and almost 50 games. Haha. For single-player game, Star Raiders (with the nifty Video Touch Pad). For multi-player, Combat. Missile Command was pretty good. Haunted House was scary, it was a game I was really "into"! Super Breakout ruled.
I never had Indiana Jones. E.T. was a tough game for a 6-year-old that I was at the time to figure out, but I managed to "beat" it. Pitfall! was the first 2600 game I ever played, but it doesn't have a special place in my heart. I hate running and jumping in one direction forever and feeling like wherever "there" was, I'll never get there.
As for Activision games, that helicopter game, Chopper Command? was my favorite. I'm not nuts about the other ones.