Most well-done anime?

[Onikasu]

.Hack//SIGN was the first Anime I ever saw that got me addicted to this better than cocaine substance, known as "Anime"
After that I found Elfen Lied. Higurashi no Naku Koro ni *adaptation or not* was done nicely. Cowboy Bebop was interesting, after that it was FLCL, then Wolf's Rain.

[Cless]

Big O the action and comedy was great. I love how they did the anime though I hated the opening theme. The final episodes left me wanting more.

[Erranty]

Big O the action and comedy was great. I love how they did the anime though I hated the opening theme. The final episodes left me wanting more.

I'm a huge fan of Big O, but we have a small difference of opinion.
I was into it more for the batman-ish feel and the jazz music.

The storyline was great and had a damn near un-copyable feel.

Yes! The last episode was messed up, it basically called it the matrix, but the good part is it came out before the matrix!

I think most of the anime that came out around 1998 was really good. Heres some of the ones that came out then:
Cowboy Bebop
Big O
Outlaw Star
Gundam Wing
Trigun
Silent Mobius

And the 2000-2002 animes were just as good:
Ghost in the Shell 2
Blue Sub #6
Cyborg 009
Gad Guard
R.O.D.
FLCL

Man those were good.

[Reon]

you sayt no fan of anime could be a fan without watching cowboy bebop-What about Neon Genisis Evangellion?

That just gives you a huge mindF*** and has become the defining series when it comes to anime.

As for most well done-in terms of art style, I'd go with trinity blood. Granted that the ending of the anime left a lot to be desired, but in terms of the art is was as beautiful as it was detailed and specific.

I agree with SnowManZero, Neon Genesis Evangelion went beyond the limitations and sparked controversy on multiple occasions because of its uniqueness. As for the remaining three, I have to go (those other than SIGN) Yu Yu Hakusho, Dual! Parallel Troubles, and Trigun. But just to name a few.

[iuliathe3rd]

Planetes was a very well done anime. It was funny, cute, and then serious, all in a nearly perfect blend. The only criticism I would give it is that the second half of the series (it's only 26 episodes) makes a drastic change from the first half.
However, the ending makes up for that. It's very much worth watching. The opening theme is also one of the best out there.

[Kay]

the animes iv seen that i think are the most well done would probly be...
The Melancholy of Haruhi Suzumiya
Genshiken
Utawarerumono
Final Approach - The chibi moments in this romance anime were done PERFECTLY.

[Shmittles The Poe]

FMA and //Sign.
Good stuff.