Lucky Star is a good anime
1) Interesting characters.
2) Good storywriting.
3) By far best anime in its category (slice of life)
4) Awesome scene composition.
5) Entertaining, it grows on you.
6) It's made by KyoAni, one of the best animu studios.
7) Japan loves it a lot.
There are many other reasons, but these should be enough, enjoy ^ _ ^