iCheckMovies allows you to check many different top lists, ranging from the all-time top 250 movies to the best science-fiction movies. Please select the top list you are interested in, which will show you the movies in that list, and you can start checking them!
500<400Favs/dislikes: 0:1. My top 500 films with fewer than 400 checks https://www.icheckmovies.com/lists/icm+forums+500dashleft400/
rare / lostFavs/dislikes: 3:1. If you know where to find anything listed here please feel free to leave a comment or DM. letterboxd.com/nbatman/list/rare-lost/