Beck is one of those animes that you look at and think "wow, the animation's kind of bad..." But after its been hyped up a bit or gotten licensed you look back at it and say "yeah the art's pretty bad, but maybe I'll check it out"
The thing about Beck is yeah, the animation isn't the best, but the music is fantastic. To its credit Beck is an anime about a band and a couple of guys trying to make it as rock stars, so it would be ridiculous if the music wasn't great.
I swear to you, the Beck soundtrack is the best one out there. I even bought it off a guy at an anime con full price even though the case and a huge crack in it.
And the music has a story behind it. it's not like they just suddenly pull songs out of anywhere, the development of songs in shown in the storyline. And you get these songs that you know. You see the characters up on stage and they start playing and its like "hey! That's "like a foojin"" and it's really great.
And the best thing about Beck is that the music is really part of the anime; it's not just thrown in. The music is what the anime's about so it's at the center, not pushed aside by terrible shoujo fanservice (not that that's a bad thing).
Beck is one of those animes you wouldn't watch unless someone recommended it.
Aren't you lucky that I did? >.-