I use extensions for the browser, such as https://elang.app/extension

Hello Salome! Well, a well known site is Netflix, you have to pay for it. I recommend it because the movies load very quickly, and there's variety (but not recent movies). There's also "Popcorn Time", you have to download it, and it's free... But once you watch the movie online, the movie downloads automatically as well. I think the best way to find online movies in english with subs is by searching "(nameofthemovie) online english sub (the idiom you want the subtitles to be in)" :)

http://speechyard.com/us/video/ is a good site designed for language learners

http://ororo.tv/en is a good website and has good series, including some from Netflix

I'm not sure about movies, but TEDtalks are really great for practicing. You can find short videos on many many topics and all of them have subtitles in at least English if not more. (http://www.ted.com)