My favorite is also a classic; Clue. Our family used to play this a lot when I was growing up. Both my mother and myself loved mysteries (we'd watch shows like Murder She Wrote together) so it was always fun to play the detective. We actually got so good at it that we were recording what each person was guessing as well as who showed what card, since that would also give some clues... Usually people would use 1 or 2 items that they already knew (either as being involved with the murder, or something they had in their hand) so as to work out the 3rd piece of the puzzle. So if a person kept asking with the same item all the time, it was a good guess that the item was either in their hand or they already deduced it was a part of the murder. Thus you might even be able to determine what card was shown even if you were not the one asking the question (or maybe figure out an item involved with a murder if no one showed any cards). We also employed other strategies as well... Once I started off the game with a guess for which I had all 3 clues in my hand; since I had all of those clues, everyone passed revealing any cards. This got everyone thinking that one or more of those items were actually involved in the murder. So I actually got my Dad to lose when he made an accusation that involved one of those clues!