XXXholic is one I'd actually expect to find a lot of fic for, but that may be a quirk of my friends list and interests. ::ponders:: Of course, most of the stories I can think of off the top of my head are crossovers with non-CLAMP fandoms. Some of the difficulty in looking for fic for it is the way that CLAMP canons and fandoms tend to interweave and to collapse in on each other. Let's see... (Pulling from the community list of friend who's into this fandom.) doumekiwatanuki, hitsuzen_100 and xxx_holic.

There's one Legal Drug community that I know of gouhoudrug. I went looking after I wrote a Legal Drug fic for a challenge/exchange. Again, there may well be CLAMP fic communities that I just don't know about.

I would expect fics for Wish to be quite rare.