Not a game console, but it was made by Atari using glorified Pong technology, so I figure it belongs here. It's an Atari Video Music, circa 1977, just before they released the 2600. It connected to both your stereo system and your television set, and generates geometric shapes which flash in time to the music. Sales were poor, and Atari pulled it from the market about a year later, making it fairly rare. I managed to pick this up for $120 from a vendor at a music-related convention; it's in good cosmetic shape, and while I purchased it untested, I hooked it up to a small TV and one of my iPods, and it works! Here are some photos of the unit, including one of it powered up and working:
Someone else's demonstration video of an Atari Video Music in action:
More on-topic, I picked up an Atari 2600 setup for $30 last weekend at a flea market. Somewhat interestingly, this one is housed inside some sort of plastic rental case lined with (deteriorating) foam. It's gonna need a fair amount of cleaning before I can do anything with it, but it seems to be in fairly good condition otherwise. Here are some photos:
Not long before that, I picked up an APF TV Fun 402 pong clone for $15. Also known as the "Sportsarama" for some reason, it includes the usual pong-type games, plus a couple of target shooting games using a frighteningly-realistic light gun. Both said light gun and the external hand controllers were included, as were the TV/game switch and power supply, though the latter has been chewed up and needs repairs. Here are some photos: