An unofficial tv-plug in Pong that had different versions like tennis etc.. Not sure of the brand but I think it was orange on top and took six of those really big D size batteries. Good times.
After that the first proper console I got my hands on was the original grey Game Boy and Tetris. I still have the GB and box tucked safely away.
Edit: Found the Pong machine I had. It was the rather fetching orange one on the right here. :D
It was a Pac Man arcade game. I had it in the living room. When out, you had to put quarters in it. When home it was free when I turned the key in it. I have never really been into video games since. I believe my brother had the first, Atari I think.