I think it varies from person to person, and how well you know the target language. Personally I enjoy watching Spanish movies with Spanish subtitles, even if I don't quite understand everything. I'm not sure if it's more helpful for my learning or not.

I read a suggestion somewhere to watch a movie you already know by heart, so you already know the plot and can concentrate on the dialogue. Or, if you have the stomach for it, keep watching the same movie over and over and over...

Watch movies with Spanish subtitles. I agree with Charlescuy. It is useful to know the story.

But NEVER watch movies with English subtitles. Otherwise you will waste your time. At first, subtitles are not the translation of 'what people say'. Subtitles are only the shortcut of the plot. Secondly, subtitles manage you to pay all your attention on reading them, not listening. So, as a result, you know the plot, but MISS THE LANGUAGE!

I know, that at the beginning such kind of watching (without understanding) will be a bit disappointing... But won't be weak. Watch these movies again and again. And one day you will understand every single word.

100% English!!

The problem with using Spanish subtitles is you then think in Spanish and you end up translating into English. It's really important you think in English!! Another benefit, is English spelling is REALLY difficult - so reading the subtitles as you hear it will help you with this.

I really recommend watching something a bit easier - watch a kids movie, or something you have already seen 100 times. Don't be afraid to watch something more than once!!

You won't understand 100%, and that's ok - more than anything, you want to be comfortable listening to English for that long. This is exactly what will happen in real life when you speak English - you won't understand everything!

I also really recommend a website / app called "lyricstraining" - you practice your listening skills in a game setting with your favourite music.

Good luck!

(from an English teacher in Mexico)