If you ever get this position ...

I suspect winning opening novelties are getting harder to come by these days, as (a) a lot of them have been found in the past and (b) computers. These means that anything really fun is most likely to occur in an obscure line which might take years before someone plays it against you.
An example of this, from one of my own games, did not happen the other night. It was a blitz game, and my opponent kindly went down the main line of the Traxler (no wimpy Bxf7+ thank you). He was even generous enough to grab my knight on move 9, a move that I remembered was supposed to be bad, but for reasons that escaped me. It turns out that it this opinion may not be accurate (in the computer age), but the line he did play was still god for me. That is, if I managed to find 13. ... Be6!! over the board. Turns out I did not, going for the obvious 13. ... Bh3+ which only lead to a perpetual.
Now I don't know whether this move had been found in analysis, but it certainly didn't turn up in my database. So if you ever get the position after move 12 on the board, you now know what to do!

Litchfield, Fred - Press, Shaun
ANU Spring Blitz, 23.09.2015

1. e4 e5 2. Nf3 Nc6 3. Bc4 Nf6 4. Ng5 Bc5 5. Nxf7 Bxf2+ 6. Kxf2 Nxe4+ 7. Kg1 Qh4 8. g3 Nxg3 9. hxg3 Qxg3+ 10. Kf1 Rf8 11. d3 Nd4 12. Nc3 d5 13. Bxd5 Bh3+ 14. Rxh3 Qxh3+ 15. Kg1 Qg3+ 16. Kh1 Qh3+ 1/2-1/2