Yeah, I did the same thing by using IMDB and assigning a rating for every movie that I could remember seeing their entirety. The problem is, I can't remember all that I have seen. I use wikipedia and their "(insert year) in film" series, but I have a hard time remembering I have seen them based on the description, as well as foreign and made-for-TV/VHS/DVD movies are hard to find.
To answer your question though, it depends. I am not quite a film buff, but I know a lot about movies and consider myself an avid movie watcher, though I usually see a bunch in spurts and have long stretches of not watching any. I like keeping track of what I have and haven't seen, so I know what to look out for. I currently have a "To Watch" list with over 300 movies at the moment, and the list only keeps on growing.
Yeah, I did the same thing by using IMDB and assigning a rating for every movie that I could remember seeing their entirety.
Also did it, though there are some documentaries and children's films I didn't rate (as are films I don't remember), a few shorts or TV specials I did... and it's still 1,044 movies!