Two hours of actual gameplay, ignoring time for people to settle in and bring arguments over whatever movie or TV show is popular at the time? Hmmm...
For D&D it would go with either a heist or escape from the dungeon one-shot with pre-gens. But my D&D games are generally 8 hours and I really don't like sessions shorter than 6 hours.
I think I would rather run a game like InSPECTREs or Labyrinth for such a short session.
But I really don't like short game nights. Even with board games. I have friends who play games during their lunch hour at work and it just isn't something I would be interested in. I would rather read, watch a show, walk the dog, take care of things around the house, or just chat with people than try to game in a 2-hour window.
It means I don't game often, but I really enjoy the time when I do.