I have a couple more to add. Games that are good both with kids and adults.
Forbidden Island. We got this only recently and played it twice - once just me and my daugther, once with a couple of friends too. And really loved it! It is a cooperative game, meaning that all players play to win against the game. The rules are easy to understand and it isn't hard to play, but it is pretty challenging. When we played it with 4 we only just managed to win and the tension was palpable. We all spontaneously high fived eachother when we made the winning move.
Highly recommended. It comes in a handy smallish tin. You do need a table to play.
And another one we just got is Bohnanza, which is a card game. Card games are so perfect for camping and travel. I've only played it once, but it's good fun. You do also need some space to put your cards down, but a sturdy book on your lap would do the trick.