Manga was CLAMP's baby, and it shows in the art from vol1-18. Elaborate, occult, and absorbing, yet unfinished. Wonderful characterization and the angstiest crossover/continuations.
Anime is s l o w, but keep at it and turns full of suspense, drama, and action. Add a killer soundtrack and at 8 DVDs, totally worth your time. Ending is complete, but a love it or hate it kinda thing.
X needs more love- just got thrown to the side thanks to ass filling like Tsubasa and Legal drug. Read it and it won't disappoint.