Brainstorm. There’s not much more to say about this card that hasn’t been said before one way or another, but I’ll put my own spin on it. Card draw in any format is just good. Being able to filter away cards is even better. While in vanilla this is really a ‘draw one’ effect, the fact that you can pitch things away with a simple Terramorphic Expanse or fetch land, as well as allowing you to dig really deep in to the library to find answers makes this probably one of the best draw spells, hands down. In EDH it has a much more muted effect on play. Players are often drawing tons of cards each turn, and the power level can sometimes leave Brainstorm wanting. Still, regardless of format it’s legal in, Brainstorm is a card that’s been a staple in top blue decks, and I don’t foresee that changing anytime soon.