Best response to the Ruy Lopez: Morphy Defense, Norwegian Variation (C70)

1. e4 e5 2. Nf3 Nc6 3. Bb5 a6 4. Ba4 b5 5. Bb3 Na5 · White to move

What is the best response to the Ruy Lopez: Morphy Defense, Norwegian Variation (1. e4 e5 2. Nf3 Nc6 3. Bb5 a6 4. Ba4 b5 5. Bb3 Na5)? White to move. See the top replies ranked by opening theory and real-game results, starting with Bxf7.

The main theoretical reply is Bxf7, reaching the Ruy Lopez: Morphy Defense, Norwegian Variation, Nightingale Gambit.