A friend recently gave us an awesome two-volume set of the ENTIRE Oxford English dictionary. Normally this takes up many volumes, but this set has been miniaturized so that the entire thing fits into two hefty books, with four regular-sized pages condensed onto each page. Reading it requires a magnifying glass, but it's completely fascinating. It gives the first known print references for every word imaginable, and many words you've never even heard of. The kids have been having fun just paging through and looking up new and unusual words.
I think we'll have to have some friends over and play "Fictionary", a game we used to play at family camp when I was a kid, which is the no-cost predecessor to boxed games like Balderdash. One person looks up a word that nobody knows. Each person then makes up a definition for that word and writes it down on a piece of paper, while the person with the dictionary writes down the real definition. Then you vote on which one you think is the real one. We had many hilarious nights playing this game at camp, but you need a really extensive dictionary to play it, especially with highly literate players.
According to the publishers, it would take a single person 120 years to type the 59 million words of the Oxford English Dictionary, 60 years to proofread it, and 540 megabytes to store it electronically