Those looking to grab one can find it on Amazon, or at Target, Barnes & Noble, Walmart, and card shops
Thassa, God of the Sea is a fine choice
It defined an entire victory condition - milling. Not too powerful, but it was epic for its time, if for no other reason than it got folks thinking about other ways to win the game. - Radagast Millstone more-or-less single-handedly invented a win condition in Magic, and created a deck archetype (and a word!) that extends to basically every card game now in existence
It turns any graveyard into a resource, applies pressure every upkeep, and is notoriously hard to remove
There are two boards Red & Blue, with the ability to capture Pokemon by hitting the pop bumpers six times in a two-minute period