Neither, I know Japanese.
...Alright, if it is a must that I have to make my decision, subtitles. My reason is simply because I want to see how they'd translate/interpret the original lines into English or Spanish. It usually gets me cracking when I see a blatant error, obscenity, or a joke that's been replaced to something that makes sense in English but still conveys the originally intended message.
On the other hand, I enjoy the Japanese subtitles for the Grand Theft Auto video game series simply because of its queer localization inspired by and riddled with bad language.