I'm sad to see that they're gone. When I first started collecting and playing designer games, they were a company that I paid attention to. Along with Playroom and Gamewright, Out of the Box seemed to approach family games and kids games with a designer touch. (To the best of my knowledge, both of those companies are alive and well)
Part of their mission statement was that their games would take five minutes or less to learn and a half an hour at most to play. Which certainly doesn't work for a lot of games but it isn't a bad rule of thumb for casual family games. And there's no denying that, even compared to Playroom or Gamewright, that was their intended audience.
While I think that the best thing they did was publish the 10 Days lines of games, which combine good game design with high educational value, I don't think I can get around their most significant contribution to gaming was Apples to Apples.
It's not my favorite party game and I know folks who utterly despise it but there's no denying it changed the face of party games. Admittedly, by being so accessible/accessible that you don't have to be creative to play. No need to know trivia or be able to improv or draw. For better or for worse, it was an ideal family reunion game. And it went to influence other game designs, Cards Against Humanity being the most obvious.
Heck, when they sold it to Mattel, I seriously had doubts for Out of the Box's future. And they did hang out for another seven years but they never had another hit like that. Still, twenty years from now, Out of the Box is going to be remembered for letting Apples to Apples loose on the world.
Looking over their catalog, they actually released fewer games than I remembered. And many of them frankly never interested me. But there were some gems in addition to 10 Days. Basari bridged the line between casual family and euro pretty well while I have had a lot of fun with Cloud 9 and Easy Come, Easy Go.
Yeah, the fact they've been out of business for close to two years and I didn't notice means Out of the Box stopped being important to me. And the games from them that have stayed in my collection are some of their older ones. But they did put out some fun games.