Simpler than many I expect to see listed here, but I'm a pretty big fan of Dominion. If the cards are always picked randomly, each play of the game is very different.
For a while each successive expansion was getting more and more powerful action cards to address this issue. Not sure if they followed that trend past Prosperity though.
That doesn't solve the problem. For any given set of 10 cards, there's an optimal strategy, and it typically involves relatively few of the cards. And some cards are effectively never worth touching in any game.