I think Ben might be manifesting some of that dry humour the British are so good at. Or perhaps your question is designed, like a tabloid headline, to start a stream of comments from alumni and students of educational institutions all over the English speaking world. Really, it depends on what you want to achieve. If you want to acquire English for academic purposes to enable you to gain entry to a university, then there are hundreds of institutions offering those sorts of foundation English courses. If you want to pursue the study of English literature in an English speaking country, then you will obviously need to spend a considerable time in an English speaking country to gain fluency.

Is this a serious question? Oxford is the answer.