K-On! is as close to perfect as any anime I've seen in a long time. It's a beautiful slice-of-life style series that follows the high school girls of the Light Music Club as they both form a band and form friendships.
Sometimes the show is almost too sweet and if you are at all sentimental (I am!) there are no shortage of episodes that will bring a tear to you eye - in a good way!
Fun, funny, cute, wholesome and all around awesome, K-On! is a must watch for anyone who likes slice-of-life style anime.