Basically, I thobl what Coop is saying is, don't nominate a game just because you think it's fun.
Nominate a game because you think that, regardless of personal tastes, it's a game that everyone should at least try.
Katamari is a good example of this, IMO.
I have a few friends who don't play much more than shooters. However, I got them to play KD just because I thought that's a game that any actual gamer should at least try, just because that's the kind of game it is. If you don't like it, fine, but but you shouldn't play video games without having tried it.
That's the point of the thread.