pokemon first gen cards Base Set | 25 Most Valuable First Edition

This is just an ordinary creature (although it is a Phyrexian Shark, which rocks) but it has Flying, and its secondary ability is very useful

Felidar Retreat, Warriors from Oketras Monument, and whatever else you make

Elder Gargaroth : A newer Wilds of Eldraine entry, this card is a creature that will allow you to draw a card whenever you cast a creature with an Adventure

Confetti Holo Cards: Look for the unique confetti-style holofoil pattern that is exclusive to this set

But to answer the question, and maybe its a bit cheesy, but I think the most surprising reaction Ive seen is just how much players appreciate the little details of the series included, truly validating the effort the various teams put into the set