Hiding Easter baskets for the kids to find. The hiding places got harder as they got older, and later we started making mystery puzzle clues to find the hiding places. Sometimes they don’t find their baskets til about Tuesday. Kept on doing this when girls got engaged, married, but SILs thought it was dumb (maybe they did not like my practice of lacing the candy with new toothbrushes, toothpaste, combs, deoderant etc.). First I felt hurt, now I just make SILs work harder for their baskets, they have an internet maze and puzzle contest to complete before they are led to a site which tells them how to claim their prize–free round of golf, baseball tickets, whatever.
We also have a Christmas puzzle or game each year as well, but now the kids take turns running it. We do the same thing when we get together in July for family reunion, kind of a mapquest.
We have other contests like making animals from jelly beans, chocolate bunny races, and we have imported confetti eggs to Cleveland (a local custom here).