Throne Room and Herald come to mind. I click one thing, then ten cards fly in front of me and I have no idea what just happened.
Another one is Procession and Graverobber. I've had turns where I did a whole bunch of stuff and I have no idea what I did, what's in my deck, I just know that it seemed good and I hoped my deck was better for it.
King's Court and Pawn, whenever this shows up, I bring out the coin tokens, Embargo tokens, and if it's relevant, some VP tokens to represent actions, coins, and buys remaining.