Pinball is more fun with friends, and as a result, multiplayer games are supported on nearly every machine built in the last few decades, and some of the ones before that. However, I find that games with more than two players tend to have too much time between your turns to play, with the result that you lose all the continuity of a normal game, so doubles pinball is probably the best.

This effect may have been exaggerated by the fact that the only friends I ever played multiplayer pinball games with on a regular basis were anywhere from moderately good to extremely good players, so ball times were sometimes way out of the norm. My writeup in the pinball and sex hypothesis has one story of a particularly long multiplayer game.