Here's one I missed way back in the day -- a vintage 1973 TV ad for Magnavox's original Odyssey, the first commercial home videogame system created by Ralph Baer:
As you can see, the Odyssey was a very simple machine -- big, white squares on a black background were displayed on the TV screen, with the color and flavor provided by plastic overlays taped onto the TV screen. The system featured "cartridges" that were essentially jumper collections, rewiring the internal board's analog logic components to construct specific games, all of which came down to moving squares.
In this ad, we can see Magnavox doing its best to inform people that the Odyssey would work with ANY brand of television, not just Magnavox sets, which was a common misconception at retail. We can also see that TV sets were relatively small at the time - no videogame system today would specifically target 18" to 25" screens. And you can see that the nascent game industry was already striving for some sort of respectability, with a Geography game.
There was no such thing as a home computer in 1973, so the ad doesn't try to evoke futuristic technological imagery -- it does call it the "electronic game of the future," but the selling proposition is that it's something fun and new to do with your living room TV.
And it doesn't focus on kids, which is an interesting and remarkably prescient choice. Best of all, it even appears that Mr. and Mrs. Lecherous Coffee Drinker are moving their paddles in synch with the action on the TV -- they're actually playing the game! I had to rewatch that shot several times to convince myself, but you can see that the player paddle is controlled by the right-hand knob, and everything's happening in real time.
Of course, videotape was also still maturing, so simulated display options were limited. And there's no great challenge involved here -- evenly matched partners can have fun at any skill level.
It's no surprise that modern Wii/Move/Kinect ads have this same sort of feel.
But in color!