Wow well, I think every anime I review is going to revolve around a boy in high school (Fairy Tail being the only wonderful exception). This boy's name is Kyon, and he meets a girl named Haruhi. She's an odd girl who claims to have no interest in "humans" and wants to investigate aliens, time travelers, and espers. Kyon helps her form a school club called the SOS Brigade which has 3 other members: Yuki, Mikuru, and Itsuki. It turns out that these 3 members are actually the things she wants to investigate. Unknown to Haruhi, they are actually there to prevent her from unleashing her reality warping powers (that she doesn't know she has). You can read more about it here.
This is a very popular and highly rated anime, and it was pretty good. But I honestly can't rate it as one of my favorites. For example, in one of the episodes, Haruhi unknowingly uses her powers and gets all the characters stuck in a time warp. They know it's a time warp, but she doesn't. The same episode is repeated EIGHT TIMES with only slight changes to the episodes, like the character's clothes might be different. I get the point that it makes you think you are in a time warp too, but it was just extremely annoying in my opinion.
Unless you've just got a lot of free time on your hands, I would skip this series. It was ok, but not one I can honestly recommend.