No, we're not talking about a bad smell. Nobody's going to pay you for that! Before all the current video-game trends like 'Halo' and 'Assassin's Creed,' there was 'Super Mario' and 'Sonic.' Before them, there were 'Space Invaders' and 'Pac-Man.' Going back even further than that there was 'Pong,' the world's first-ever home video entertainment game.
'Pong' was a simple affair - a sort of tennis game where two players could bat a square ball from left to right across the television screen, scoring points when their opponent was unable to return a shot. It would be considered incredibly basic by modern standards, but at the time nobody had ever seen anything like it. If you (or more likely your parents or grandparents) still have a working copy of Pong somewhere in their homes, it's currently worth up to $5,000 at retail. It may go even higher as the years pass, and more people become curious about how video games started.