Quantum theory was certainly revolutionary, and it still clashes with human intuition as forcefully now as ever. There is a never ending debate over which "picture" captures the "true, physical meaning" of QM, but of course they all make the same predictions...

Evolution makes a bid, but after all it's only life on earth. Finding out that the entire universe behaves like nothing you would ever dream of is hard to trump.

"Anyone who is not shocked by quantum mechanics has not understood it."