Always visible indicators for state
I find myself hovering over the posters a lot to see if I've come across them and marked appropriately. Would be nice to have some small, always-visible indication that I'd done something with a film.
Wouldn't have to note the watched/liked state (though I supposed you could simply with colour). Just that you acknowledged the film as something I'd touched.
Oh yes, I wish I could see if I already added a movie in my watchlist, if I watched or liked it.
It is so boring that I have to hover (or click in case of watchlist) on the poster to know any of those things.