Wish is one of CLAMP's definitely less popular series; and it's rather difficult to find quality sites , actually any site dedicated to it. Do you own a Wish site which I'm not including here? E-mail me its URL ! ^_^
I'll list those which I find to be well set-up and overall interesting to visit:

General Websites

  • Your Eden... - http://sakurazukamori.net/eden
    Val's wonderful "Your Eden..." is a definite must-visit for anybody who is interested in deep character analysis and other great content. Go there, now ! ^^

  • Usyagi's Wish Site - http://come.to/mywish
    To be quite honest, I am not too sure whether Usyagi's Site is still being updated... but nevertheless, it offers good overall information on the series, with original things such as a description of the gemstones featured in the series and other nice things. This was probably the first english site to go online ^^

  • Spanish Wish site - http://www.geocities.com/umi_chan...
    Ummm, a Spanish Wish site? ^_^; ... it's one of the few more recent ones, and it seems to still be taken care of ^^v

  • Fulfill my Wish - http://ryuuzaki.org/wish/
    A nice, new addition to the online Wish-site-community. Very text-based with a lot of nicely written information.

  • Tears in Heaven - http://www.envy.nu/wishtears/
    And yet another page I only ran into very recently! ^^ ... It's got all the basic things a general site needs with some cute multimedia.

    Character Shrines

  • X-Playboy - http://cherry-blossom.nu/kokuyo/
    A small but promising shrine to my second favorite character; Kokyou. It's nice to see a dedication to him out there ^^

  • Black & White - http://megitsune.net/kokuyou/
    Oh, people say Kouryuu's the popular bishounen in WISH, but actually Kokyou seems to be the one that is getting more & more shrines! ^_~
    At any rate, this shrine is nicely done with a *very* good, analytical character description.

  • Daisy! - http://www.cherries.nu/Daisy
    A petite shrine to the series' adorable "mascot", Usyagi. Find out why it's not only adorable but also crucial to the story! ^_-

    Online Wish Reviews

  • @ Anime Genesis - http://www.anime-genesis.com/...
  • @ EX.org - http://www.ex.org/2.5/27-manga_wish.html