Without a doubt, a love story. I mean, sure mysteries are great. They're interesting, suspenseful and really addictive. But when you compare it with love, how could love ever lose? The power and strength of the human heart, the true love between two souls... What could really compare? To me, love is amazing. It's unexplainable.
Actually, it isn't even a fair competition between the two genres. I've loved romance ever since I read my first one when I was about 14. Since then, no other genre has made me so crazy over it. So definitely, a love story is my answer.