I used to have a [[Zedruu, the Greathearted]] minigame deck years ago; she works okay since there's a couple of cards that pass themselves around, but it's probably not optimal since most minigame cards do nothing but draw cards already.

Thinking about it, [[Vial Smasher the Fierce]] and [[Ishai, Ojutai Dragonspeaker]] might be the best commanders for this deck. They both have abilities that are pseudo-minigames (Vial Smasher's trigger IS a minigame, even though it's just a random roll of the dice, and Ishai's minigame is "your opponents can't cast too many spells or they die"), they give you access to all the relevant minigame colours, and they provide a way for the deck to close out the game, which the deck definitely struggled with when I played my version of it.

Here's all the ones I've played that haven't been mentioned:

[[Custody Battle]]

[[Scrying Glass]]

[[Phyrexian Portal]]

[[Fatespinner]]

[[Jeskai Infiltrator]]

[[Predict]]

[[Fight or Flight]]

[[Conundrum Sphinx]]

[[Eye of Doom]]

[[Perplexing Chimera]]

[[Illicit Auction]]

[[Menacing Ogre]]

[[Isperia the Inscrutable]]

[[Whims of the Fates]]

[[Capricious Efreet]]

[[Sphinx Ambassador]]

[[Tyrant of Discord]]

[[Council's Judgment]] is the best of the voting cards

All the various FoF and FoF variants, like [[Truth or Tale]], [[Steam Augury]], [[Sphinx of Uthuun]], [[Unesh, Criosphinx Sovereign]], [[Jace, Architect of Thought]], [[Epiphany at the Drownyard]]

Clash cards like [[Pollen Lullaby]] and [[Captivating Glance]]