Okay. I am going to take another stab at Lucky Star. Third time's the charm
Ah, I love Lucky Star. It falls into that beautiful category of anime (along with shows like Aria and Hidamari Sketch) which are slow, relaxed, not all that interesting, really, but ridiculously calming. The sort of anime you watch when you're really stressed after a long day at work, or when you want to unwind a bit before going to bed. It's not really all that good to watch as a proper TV show, if you get what I mean, but it's a wonderful show all the same. I wouldn't advise trying to marathon it, if that's what you were planning.
EDIT: And Tamayura! Tamayura is another perfect example of the genre I mean. Much more so than Hidamari Sketch.