Shoujo Kakumei Utena has the best anime soundtrack ever. Shoujo Kakumei Utena: Adolescence Mokushiroku movie has a very good soundtrack as well.

Even though I joined in 2008, I restarted my lists with only only the manga I've read since 2012 July!

I really liked Zettai shounen, both the anime itself and the music

Ah My Goddess
Air
Bleach
DearS
DNAngel
Ergo Proxy
Ichigo 100%
Inuyasha
Mahou Sensei Negima
Rurouni Kenshin
Trigun
Tsubasa Chronicles
Witchblade
Wolf's Rain
xxxHolic

I find that all of these are good, or at least have one or two good songs.

Cowboy bebop
Trigun
Samurai Champloo
Aaa Megami Sama
Earth Girl Arjuna
Macross Plus
Gyakushu No Char

Ah! My Goddess
The Vision of Escaflowne
Full Metal Alchemist
Full Metal Panic
Darker than Black ( The intro song )
Nogizaka Haruka no Himitsu ( The Ending )
Trinity Blood ( intro and Ending.)
. .
. Can't remember anymore at the moment.

Nana..soooo good the music
and the opening and ending of vampire knight anime!! but I have no idea if there is any music while during the episode

You know, you love me

Waa, I can't believe no one mentioned .hack//SIGN! There's some cool vocal stuff in there. In fact, anything Yuki Kajiura. Anything Yoko Kanno too. As far as I'm concerned, they're pretty much the gods of anime composition. Yoko Kanno more so, but Yuki Kajiura's style really speaks to me.

To list some more by name: (this is based fully on music, not necessarily plot, and the background music, not the opening and ending themes)

Noir (some lovely typical Kajiura, powerful strings and unusual, but lovely, vocal music, all in a style that creates a unique feel, the series also has a 'music box' theme in the music <says the one who's only seen two episodes and just listens to the music a lot...>)
Fullmetal Alchemist (a lot of classically-influenced orchestral stuff, not really the sort of music that I just want to go around listening to, but it goes very well with the anime)
Death Note (some of the music in this series reminds me a lot of Final Fantasy music...)
Cowboy Bebop (enough to say, Yoko Kanno is amazing. The diversity of styles is incredibly impressive, stuff that I want to listen to straight has hardly seen any of the series, I really I need to get around to doing that...)
Rurouni Kenshin (there are some powerful string pieces to be had in this series... I swear, that one scene wouldn't have made me cry if not for the music. It hit me...)

Don't feel like listing any more at the moment... Ooh, Ouran. Some cool stuff there.

And an ending note, keep on the look out for any songs that have Steve Conte. He does vocals in some music my Yoko Kanno, and his voice is amazing... is currently grooving to Living Inside the Shell from Ghost in the Shell: SAC

I don't know a lot animes who have decent music during the episode but I know a lot with nice EDs and OPs.

Naruto
Bleach
Neo Angelique Abyss
Code Geass (nice vocal stuff during the episode)
Sousei No Aquarion

In order:

Kigeki
Escaflowne
Cowboy Beepop
Beck
Suzumiya Haruhi no Yuuutsu

What I like in Trivial Pursuit style. Pick your category:[img]http://i379.photobucket.com/albums/oo233/Reid4891/Manga/trivia-1.jpg[/img]

Gunslinger Girl has very good scoring throughout the series.

• D.Gray-Man ( Specially love the 14th lullaby(best in-song ever))
• Nana ( Love their bands songs xD )
• Bleach ( Love the openings and the battle music )
• Tengen Toppa Gurren Lagann ( had some good songs^^ )
• Nodame Cantabile ( If u liek classic music )
• Macross Frontier
• Ah! My Goddess
• Naruto ( some of the openings, but the anime itself sucks 🙁 )
• Air Gear
• Eureka SeveN ( Love the OP´s, ED´s + IN´s )
• FLCL ( a.k.a Furi Kuri )( has some good songs )

Cant really remember so much more atm, sorry xD ^^

Definitely Blood+ if you are a cello fan.

There is a problem with you if you aren't.

Death Note also has a AWESOME score.

Mello's theme anyone?

[img]http://s4.tinypic.com/23jr85h.jpg[/img]

Quote from shaggievara

Definitely Blood+ if you are a cello fan.

Yeah.... but the actual plot was disappointing, IMO.

Of the more recent 2008 anime, these have pretty good scores;

Kaiba
Mugen no Juunin (Blade of the Immortal)
Natsume YuujinChou

Kure-nai has some nice music as well, but ignore the intro and ED songs.
If you want something a bit more mainstream, maybe something like Soul Eater.

Point & Squirt

Karin
Kannazuki no Miko
Kakyuusei
Ranma 1/2
Hell Girl (Both seasons)
Shaman King
Prism Ark
Inukami
Keroro Gunsou
M.D. Geist

Eureka 7 has many good songs

"we are people because of other people"
"I am who I am because of who we all are"