Ok, mine was Mario both single player and multiplayer...remember Luigi...? Used to play it on a Goldstar VCP with a in-built video game deck.
When I had my PC back in '99, I got addicted with Battlezone...It was a great game, the soviet missions were harder and more enjoyable. Infact remember that it was the game of the year 1999. Pity after BZ2, Activision did not release any other sequel...