twofifty.org lets you track which movies from the IMDb top 250 you’ve seen. My twofifty.org list has 71/250 crossed off.
Twofifty.org to track movies
I use twofifty.org to track my progress through the IMDb top 250 movie list. I've currently seen 71 out of the 250 films and am using this tool to manage my watchlist.