Haruhi Suzumiya is a great show with characters who grow on you from the first episode. A lot of the show is carried by the narrator, who also plays one of the main characters. His voice portrays the character's annoyance and cynical outlook perfectly, and his cynicism is nicely offset by Haruhi's craziness.
The show is mainly done as a slice-of-life type anime, but there is a plot arc in there as well, which has to do with sci-fi, aliens, a group from the future and time travel. Oh, and superpowers. But it's all taking place in an everyday high school setting. Sounds crazy, and it is - you just have to see this one.
I can't wait to see a second season of this incredible show.