I prefer to watch movies with subtitles. I do understand english language pretty good, but still it is easier for me to watch a movie subtitled in my native language. It is easier for me to follow the movie. There are some specific expressions that every language has which you may not understand if it's not your native language. Also accents in the movies are different, some are harder to understand and some are easier. Watching movies with subtitles is a great way to learn new language. So, to sum up, I generally just feel more comfortable to watch a movie with a subtitle, although I can easily watch almost any movie on english language without subtitle.