How shall I put it... I've given a look at the first episode. Uh.
If I want to watch a show where the music was composed by the creator/writer, I'll watch Kaamelott. Plus, the man is also the director, main actor and generally a nice guy.
If I want to watch a surrealistic high-school show with a fantastic soundtrack, I'll watch Revolutionary Girl Utena.
If I want to watch a Japanese production with a soundtrack of timeless classic proportions, and that's about a purgatory world where you have to help your friends 'cross over', I'll watch the Haibane Renmei anime show. If I just want a purgatory story stuck in reality with a nice OST, I'll go for the 'Afterlife' (Beautiful Life) live action movie.
What I mean is, I'm not really sure what's in it for me with Angel Beats. It looks like a basic high-school show for zettai-ryôiki otakus. The guy wrote Kanon -- I've heard so many people say it's a fantastic show, but it doesn't cut it for me because the character-design is so awfully lolicon with wide eyes that make me wanna puke.
Alright, I didn't put it properly but I'm all ears :P
Great anime soundtracks for me: Saint Seiya, Kaze no tairiku (Weathering continent), Kamui no ken (Dagger of Kamui), Arete Hime (Princess Arete), Ie Naki Ko (Nobody's Boy Rémi), The Mysterious Cities of Gold, Berserk, Kaiba... This one being probably the most recent show that drew me to it. It was like 5 years ago... I haven't since seen a show that grabbed my interest, soundtrack-wise. Apart maybe from the psychedelic 30-minute version of the opening to Eden of the East, but it was written by Noel Gallagher... Hardly a typical anime song... ;)
Oh my, I so want to discover new interesting Japanese soundtracks!