Aaaah, Atari. I saved my allowance for Atari games and nothing else in the early 80s. I don't think I ever bought an M-Network game, but the commercial made me feel good about my gaming system and summer (which is when these commercials aired). I had a friend who rocked an Intellivision. He was a loser, though he argued his platform with a dreadful ferocity.
Pitfall. Oh, gawd I loved this game. I was in love with the wild adventure of Indiana Jones (there was only one at the time), and as far as video games go, Pitfall Harry was the shizzle. The game's main flaw was that it put a 20-minute timer on the gameplay. You had to get as much gold and booty as you could in 20 minutes. Unfortunately, there was no clear objective, so you were left with your greed as motivation. Watch for a young Jack Black right at the beginning.