"Window to the Future" by FISM-winner Henry Evans starts with a prediction placed inside a clear glass. You then introduce a deck of cards with a totally different colored back and allow the spectator to take about half the deck and shuffle it.
This shuffled half is then split up into packets with different amounts of playing cards in each. They are allowed to shuffle all these packets separately and then choose one. The final selected packed is then shuffled.
Everything is super fair. So, what happens next truly feels impossible.
You show that your prediction was not only correct about the amount of cards they would choose, but also has the exact same cards in the exact order. A perfect prediction.