Hahah, I just mentioned this on the other thread, but I vastly prefer the Revolutionary Girl Utena anime to the manga. The manga is just... meh. >< I have equal love for the Sailor Moon anime and manga. From what I've read, I think the Furuba and Loveless anime were also good adaptions of the manga (though granted, I've not read all of either manga but watched all of both anime).
For Clamp, the HOLiC anime was a good adaption and the Tokyo Babylon OVAs in general caught the manga very well, without trying to make the OVAs -be- the manga. They were just side stories that completely fit the manga canon.