I find this one to be extremely instructive.
It's not really a puzzle, the move Anand played is not winning on the spot, but it's the only move that gives black an edge (the computer says -0.9).
As a hint, this is what Magnus said about the move: "It's not an antipositional move, it shows wonderful understanding". (This is what makes this move so good)
What do you think Anand played here?
This is the complete game. It's still regarded as one of Anand's best games. Check it out after you find the move.