In the ChessBase database of 4.8 million games. more than 400 thousand reach this position:
In nearly half of these games White played 3.Bb5. The second most popular move 3.Bc4 (the Italian opening) has 95 thousand fewer games.
No opening is more popular than the Ruy Lopez, or Spanish as it is known in some circles.*
Edit: It has been pointed out to me, correctly, that the Sicilian Defense is more popular than the Spanish Opening. The Sicilian's popularity begins in the late nineteenth century.
14 minutes ago