For myself, my answer to this poll is, best friend's stuck up bitchy sister. In my case, it would be co best friend. My best friend's sister is 40, married, fairly nice, and not that ticklish, so I really dont have a thing for wanting to tickle her.
I dont know how ticklish my co-best friend's sister is, but she's 32, and one of the biggest snobs one would ever want to meet. I've never tickled her, or even seen her feet, but if I ever had a tickle victims list for people I know, especially ones I'd like to teach a lesson to, she probably would be at the top of that list.
Mitch