I'm excited to get to play Towerfall[0], one of the console's "launch titles", having been released only a couple days ago.
Action games focused on local multiplayer like Towerfall and 0space[1] are the most enjoyable experiences I've had with video games. In my mind, it's games like these which can attract people who otherwise wouldn't be interested in buying a console. That is, when you see games like those being played, it's easy to see who's winning and how, making it much easier to access.
[0]http://www.towerfall-game.com/ [1]http://teknopants.com/games/0space/
Especially 0space, that game is amazing. Samurai Gunn, from the same developer is also very good. Although I haven't heard any rumours of Ouya, I think Gunn is now being ported for Vita (and possibly PS3/4 I suppose)