I didn't enter my most common passwords here. Pretty decent site. I tend to do well with this kind of thing.
What I was careful to do was to create something out of words that would make sense to me but not to any other people, so that if the algorithm tries combinations of words, it won't get it. Additionally, it's long enough to be reasonably secure.
I had to work pretty hard to think of something like this because I tend to have difficulty remembering arbitrary words or phrases.