1.e4 e5 2.Nf3 Nc6 3.Bb5 f5!? This (I've heard) is one of the sharpest defenses against the Ruy Lopez. I personally don't like the Ruy Lopez.
I know this variation goes 4.Nc3 fxe4 5.Nxe4 d5 6.Nxe5 dxe5 7.Nxc6 Qd5! 8.c4 Qd6 9.Qh5+ g6 10.Qe5+ Qxe5 11.Nxe5+ c6 12.Ba4 Bg7 13.d4 exd3 14.Bf4. If white moves 12.Nxc6? is 12...a6! 13.Ba4 Bd7, which will win a piece for black.