Breath control: A fantasy, but way too scary to do in practice. It's kinky to think another guy was in control of me, even to deprive me of air, but it's a quick way to death, so I just think about it. Sometimes.
Cows: "I like cows, and they like me" by the late great Minneapolis band The Suburbs. I did the rodeo this summer and had a great time with the steers. Rasslin' em, getting them into the chutes. I feel like a bull most of the time.
Force feeding: Ok, a little strange of a fetish. But it goes with the control thing. Another kinky thing I'm never really done in person. Ok, a few times, maybe.
Mummification: Wow! Combine this with a blindold and earplugs. Total sensory deprivation. And then the fun starts... either leave me there for a long (long) time, or give me something to think about.
Sleepsacks: I had one that was too scary for me - complete rubber with only two nose holes. Your arms go in these sleeves, so you can't even touch yourself. I never actually slept in it... it was terrifying.
Uniforms: All kinds - military, blue collar, atheletic. I like working men, and a uniform is a great equalizer. When everyone looks the same, it makes you concentrate on the man, not the clothes.