Shapeshifters like Vesuvan Drifter from MOM: The Aftermath are also good options, and Dimir colors are perfect for accessing lots of the best rogues in the game, like Frogtosser Banneret for cost reduction
However, Fallen Empires was the first time a set was entirely designed around creature types, with each color representing factions that prominently featured one or two creature types
Skullclamp Most of the best cards in this ranking cost between $20-40, but you can get Skullclamp for a fraction of that, thanks to its many recent reprints
Black Market Connections Black Market Connections is the card that buried Phyrexian Arena for me, at least when budget isnt a concern
While Minds Desire remains the only banned Storm card, bans have been made with the explicitly purpose of weakening storm decks
And all those cards are good in the deck without the combo coming to bear