A magnificent question, if I may say so myself.
There are several candidates:
1) One of my newest, and dearest friends, a girl who works across the street from me, a girl who's been to my house with her husband for dinner and drinks. I got her to admit (through some manipulative, even arguably underhanded means) just how ticklish she is, and in what particular places. Given that she has a natural Betty Rubble laugh, I'm imagining that applying fingers to her would be a heavenly experience.
2) A girl who works in a deli/news stand at one of the nearby train stations. I've known her for years now. I don't know whether she IS or not, never talked with her about it, never actually got close enough to even try it, but I think she likes me. Likes me. One day, I'd like to hang out with her, if she got a break, and just see, maybe. Poke a finger, you know?
3) The inimitable, marvelous Belle of Wisconsin herself, the Majestic Mimi. I hope that one day, my fingers can happily meet her flesh. Ah, the wonderment.