While this game does have some prep work, during the party it takes very little of your time. It also comes with the added benefit of a built in prize for the winner(the basket).
Fill an Easter basket with loads of different small candies like jellybeans, foil wrapped chocolate eggs, and Hershey Kisses using lots of Easter grass to keep most of them hidden. You can also add a few larger items like a stuffed bunny or candy bars, but pay close attention to exactly how many items are in the basket.
At the start of your party place the basket on a table with slips of paper, pens and a cardboard box with an opening cut in the top. Challenge your guests to figure out exactly how many items are in the basket (no touching allowed). When they are ready to guess, they write their name and estimate of the number of items on a slip of paper and drop it in the box. The person closest to the actual number wins and gets the basket and all its contents as a prize.