Read this: There are many accents that are traditionally thought of as London accents. The most well known of the London accents long ago acquired the Cockney label, which is heard both in London itself, and across the wider South East England region more generally. The accent of a 21st-century 'Londoner' varies widely; what is becoming more and more common amongst the under-30s however is some fusion of Cockney with a whole array of 'ethnic' accents, in particular Caribbean, which form an accent labelled Multicultural London English (MLE). The other widely heard and spoken accent is RP (Received Pronunciation) in various forms, which can often be heard in the media and many of other traditional professions and beyond, although this accent is not limited to London and South East England, and can also be heard selectively throughout the whole UK amongst certain social groupings.

What is the best-known London accent known as?
What is the answer? (If it cannot be answered, return "unanswerable")
Cockney