I also manually deleted every piece of content that I could find before I deleted my account. The hardest part was finding comments that I had made on other people's posts, because often I would delete the mention of it on my own profile. However, Facebook has a facility to "see frienship", which will dig up these comments. So I actually visited every profile of several hundred people and went to the "see friendship" page, then deleted everything I could find, every comment, photo tag, etc. It took a few weeks to get to the point where I was satisfied that no trace of me existed on Facebook (at least nothing that could be accessed by users), and then I deleted my account.

Six months later, I still have no desire to go back.