Ouran High School Host Club - gotta love this show from the opening theme to each and every comedy filled episode
Rurouni Kenshin
Fushigi Yuugi: The Mysterious Play

Ouran High School Host Club
Fruits Basket
CardCaptor Sakura
Bleach
etc..

I never get bored over it!
Love the storyline and everything else about it!
=D

I will definitely watch again: Glass no Kamen, Touch, Evangelion, Nana, Kareshi Kanojo no Jijou, Attacker You, Maria-sama ga Miteru, Kodomo no Omocha, Utena.
I like the kind of anime where you don't get most answers you're looking for, not even at the end- I think Evangelion is a good example of that- it remains mysterious.

YU YU HAKUSHO

Trigun and cowboy Bebop
as far as Full length Features Princess Mononoke and Akira

never got tired watching over and over
slam dunk,samurai x,fate/stay night, ranma 1/2, kare kano, xxxholic ^^ such good shows

I could watch Claymore over and over again

Ranma 1/2, Macross, Full Metal Panic, Slam Dunk. I never get bored watching these.

Well, there are still too many animes I want to watch, so for the time being I won't watch anything over and over again
But I plan on rewatching 12 Kingdoms, Haibane Renmei, Koi Kaze, Zettai Shounen, Kino no Tabi, 100 Stories (and probably some other I don't remember right now) because they are just so good

OH O_o that's hard! but emm...
studio ghibli films
kaleido star
fruits basker
honey and clover
princess tutu
ouran high school host club
and so on^^

Shuffle, Nanoha, Nanoha As. I'll just leave them on and do my programming, while not really looking at the things going on. Somtimes does distract me a little when it comes to the exciting parts.

There are a few I watch over and over again, without a second thought.
- Tenkuu no Escaflowne;
- Air;
- Mononoke Hime;
- Full Metal Panic . The Second Raid;
Mostly, my favorite animes.

eva, hellsing, dragon ballz, elfen lied, blue seed, and some i cant think of right now.

Here Mine.

Black Cat
Bleach
Air Gear
Fate/Stay Night
etc.

Fate-Stay/Night...dunno why, just want more of Sabre
Initial D...god it's so badly drawn, but the story and the driving are CRAZY!
Chobits...Chiiiiiiiiiiiiiiiiiiiii?
Strawberry Panic...ZOMG why the hell did I put a yuri here...oh well...
Wolf's Rain...I love wolves, I love action, I love just a HINT of romance...and it's all in Wolf's Rain...

GTO
I never get tired of watching that show.. Onizuka is the most hilarious character, both in manga and in the anime. I could watch that show over, and over and over and over and not get tired.

I can't believe no one else listed this..

Any comedy series. The ones that come to mind are Puni Puni Poemy, Azumanga Daioh, and Excel Saga

R.O.D the TV for me. I love the characters so much that I could never get bored watching the show. Same for Shrine of the Morning Mist.

the anime i would watch over and over is full moon, kaikan phrase, ayashi no ceres, aishiteruze baby, basara, this ugly yet beautiful world.

Definitely Sailor Moon all the way!

-Ouran High School Host Club
-Suzumiya Haruhi no yuutsu
-Lovely Complex
-Eureka 7
-Shakugan no Shana

considering i watche DBZ hella times, cause of stupid cartoon network, i might watch that again =p...id prolly end up watching:
Death Note
Air
DBZ
Clannad - even tho its not done
and i heard Tengen toppa gurren lagann was really good so maybe that =p

For me is Yu-Gi-Oh!,Naruto and Ouran High School Host Club

Usually funny/cute/sweet/awesome anime, like:
Hayao Miyazaki's works (e.g. Totoro, Mononoke Hime, Nausicaa, Spirited away ...)
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Saiyuki
Inuyasha (preferably episodes without Naraku) ...