All CLAMP Animes
Anime
Don't watch CLAMP animes, they always differs from the original manga. But if you're gonna ignore me then here you go the list of the main titles.

OVA, 1991,
2 eps
Me:-
Author:-
Really, don't watch this, especially this, just read the manga.

Movie, 1996,
1 ep
Me:-
Author:7
The director: So, what is this about?
The crew: Is mainly a battle royale but-
The director: Let's go with that.
To be fair, there is no way you can make a good adaptation of this manga in a movie, you just needs a long span series, they made what they could.
The crew: Is mainly a battle royale but-
The director: Let's go with that.
To be fair, there is no way you can make a good adaptation of this manga in a movie, you just needs a long span series, they made what they could.

OVA, 2001,
1 ep
Me:-
Author:7
It's like a zero episode, but i don't recommend you to watch it before.
1. Because you wont understand a shit if you haven't read Tokyo Babylon, and you'll get spoiled btw.
2. Because it's a preview so you'll get spoiled.
1. Because you wont understand a shit if you haven't read Tokyo Babylon, and you'll get spoiled btw.
2. Because it's a preview so you'll get spoiled.

TV, 2001,
24 eps
Me:-
Author:9
Since the manga is in hiatus since 2003 i recommend you to watch at least the end of this anime. Episodes 1-14 adapts manga volumes 1-10, heavily abridged of course. Volumes 11-17 were adapted in episodes 15-20, this is where the anime starts to heavily differs from the manga. Volume 18 was left unadapted and episode 21-24 featured an original ending to the story.

TV, 1994,
20 eps
Me:-
Author:-
This season doesn't differs so much from the manga.

TV, 1998,
70 eps
Me:-
Author:-
One of the best adapatations, and one of the most faithful, but even so read the manga.

Movie, 1999,
1 ep
Me:-
Author:-
As much successful animes, CCS got a movie featuring an original story. It was released after episode 46 in august 21, 1999, during a 3 months hiatus.

Movie, 2000,
1 ep
Me:-
Author:-
A sequel/ending to the series.

OVA, 2017,
1 ep
Me:-
Author:-
This is a remake of the series finale to match with manga's ending.

TV, 2018,
22 eps
Me:-
Author:-
I don't know why the Prologue exists, because latter in this series they add things that come from the original anime and doesn't match the manga.

Movie, 2005,
1 ep
Me:-
Author:-
A movie released the same day as XXXHolic movie, featuring an original story that takes place at the same time of the later, emulating the original mangas relation.

Movie, 2005,
1 ep
Me:-
Author:-
A movie released the same day as Tsubasa movie, featuring an original story that takes place at the same time of the later, emulating the original mangas relation.

TV, 2005,
26 eps
Me:-
Author:-
The perfect introduction to the CLAMP Multiverse, and although this anime is severly toned down it's a good enough adaptation.

TV, 2006,
26 eps
Me:-
Author:-
Unlike the first season this heavily differs from the manga, besides almost 90% or so is original, so not recommended.

OVA, 2007,
3 eps
Me:-
Author:-
For this, the most important Arc, the manga was adapted in a 3-episode OVA, the tone was left as it is in the manga.

TV, 2006,
24 eps
Me:-
Author:-
Although a good adaptation it cuts off any relationship with Tsubasa Chronicle. Even so, it's a good stand-alone ghost-themed anime.

OVA, 2009,
2 eps
Me:-
Author:-
This is the first entry in the series to feature a Crossover with Tsubasa Chronicle, so you NEED to know the Tsubasa's story.

OVA, 2009,
2 eps
Me:-
Author:-
For narrative purposes this OVA was released between the two episodes of XXXHolic Shunmuki, but the story takes place at the same time. Apair of arcs were skipped.

OVA, 2010,
2 eps
Me:-
Author:-
Adapts part of the final of the manga, but you probably won't understand at the beginning if you haven't read at least Tsubasa Chronicle

TV, 2011,
12 eps
Me:-
Author:-
This doesn't feel as a CLAMP work, because it is not. According to wikipedia it was co-written by them and Junichi Fujisaki. It's part of the Blood Franchise.