I'm not interested in nudity in tickling videos. To me, having the ticklees keep their clothes on (except their footwear) makes it easier to identify with the models and situations, since it's closer to an ordinary, everyday situation for most people, including myself. I mean, when I was younger and had a bit of tickling fun with friends, they weren't exactly nude. So when there's clothed tickling going on, it's easier for me to remember those good old times.
I also feel the "innocence" of it makes it more appealing. After all, to most of us, tickling is erotic to some extent, right? Well, the way I see it, as far as "erotic" is concerned, nudity is just too obvious. To me it makes a special scene appear too bland, because there SO MUCH nudity all over the place. Same old same old. But to see it done to an ordinary, fully clothed ticklee, who doesn't seem to be in "sex mode", almost seems more naughty to me. I don't know, it's just how I feel.