So, are you looking for a website where you can organize all of the anime you have seen? If so, then Anime-Planet is the place for you. Anime-Planet is an anime database were you can easily organize all of the anime you have seen; are currently watching; want to watch; and won't watch. The great thing about AP is that it will show you how much time you have spent watching anime. If you are looking for a new anime to watch, you can check out the user recommendations. Lets say you liked Code Geass and you want to watch an anime similar to it, just look at what the users are recommending. The recommendations here give out valid arguments on why you should watch it.
AP has recently unveiled version 3.0 to the public. Version 3.0 has a lot of brand new features like blogs and friend list. I have been using AP since January of last year and I love it. AP helps me so much because I tend to forget what anime I want to watch. AP also has a great manga section that is currently growing.
AP also has a great forum with a lot of friendly people. What I like most about the forum are the clubs. By the way, I'm a moderator there and when you join, please read the rules. So, come on and join Anime-Planet.