I've met Da1AndOnlySonic many times, he is awesome. He shares his strategies with me and we think very alike...it's almost as if we're the same person.
Anyway, in all seriousness, I would say that I've met a fellow TSC player, but I knew the person before they became a part of TSC. In my opinion, that doesn't really count. :(
However, there are a good amount of TSCers I'd really like to meet in person, they know who they are.