Naruto

Many years ago, in the hidden village of Konoha, a beast known as the "demon fox" invaded the land and caused the death of numerous villagers. It was quite unfortunate that the fox's soul was sealed into a baby boy named Naruto. Ever since that event, the boy has been neglected by the people around him. Many would blame the deaths of the villagers on him. Due to this, he has had a very painful childhood. In addition, little is known of his family origins, so he grew up alone, and didn't have a lot of friends. But despite this, the boy grew stronger through the process. There wasn't any leading villain up untill the Chuunin exam. This was where Orochimaru came in. Ever since then, the series was even more intriguing.
Naruto is the best anime series I've seen. The storyline is packed with action, and each episode causes you to anticipate what comes next. I find the series very exciting. There are many episodes (over 150!), but they're all worth watching. Over time, we learn a lot about the characters' origins and childhood. The most information was given related to Sasuke to Naruto, but we discover more about the others later on in the series. Some new characters are developed over time, take Tsunade, Jiraiya, Shizune, Orochimaru as examples. These characters didn't appear from the start. Rather, they were introduced in between the series.
Over all, I do recommend this anime series, and rate it 5/5 stars.
Thanks to theotaku.com for the image!