I have watched quite a few sports anime and I have to say that Haikyuu is so far the best of them. Most people would argue that Kuroko's Basketball is the best. Yes Kuroko's Basketball is really good but there are too many elements that just seem unrealistic. Haikyuu on the other hand is more down to earth and seems to be as close to reality as possible. The anime is more serious than its other counterparts and concentrates less on the ecchi/harem themes, which is a great thing.
I just love the story, the soundtracks, the characters and the pacing of the anime is quite good too. The artwork is more than adequate as well. To people planning on watching this- you won't be disappointed!!