K-ON! Is a very great Anime to me. I thought the story was a pretty great idea, a teenage girl who goes to High School and ends up joining a band. They then go through many humorous events as they pass through school. It just kept me sitting at the computer all day.
The Animation was pretty good, just not as good compared to other Anime's animation, but the Character animation was well!
The sound was pretty good, the noises of the instruments sounded real, and not dodgy. The sound matched up with certain moments too.
"The Characters were well for this Anime", I thought. They all fitted like your average band, people who have different thoughts. While Yui is very cheerful and playful, along with Ritsu who is very energetic, and sometimes crazy, so they get along. Then there's Tsumugi who is very kind, and gentle, she will often cheer people up if they are depressed or fighting. Mio is very shy,and very paranoid, she often gets scared a ton, but it's what she's like that keeps humor. Last, but not least, Azusa, she's very kind and somewhat nervous, she sometimes doesn't like it when she is bothered by the other 2.
Overall, K-ON! Was a good experience, and you should try it out, you just might like it.