Heights, only when I feel out of control. Rock climbing for instance I feel like my belayer is controlling me and nit myself as I KNOW I am.
Clowns. Not so much anymore but when was a kid there was some in our annual parade so I calmly moved away from the curb as he said hello to my friends, then he came to me, I backed further off the sidewalk and he kept coming at me. Yes clearly advancing on the terrified child is a GREAT idea! I about kicked him in the face.
And peopling big costumes, like mascot costumes ever since my friend made a seemingly harmless joke about them being able to hide weapons under their costumes
Equestrianism; 10% luck, 20% skill, 15% concentrated power of will, 5% pleasure, 50% pain and 100% reason to remember you're absolutely insane to be riding a beast that big.