I love the website simply because I can see on which classics I'm missing out, and because it introduced me to some great movies. The UI is incredibly well designed, which only makes it all the tempting easy to get hooked on the site. Thus far I've ticked 225 movies, and counting. You should totally try it out.
Oh, and you can totally compare your lists with "friends". Feel free to add me, my username is Snail.