Beside LBS, LSE, Imperial and Cass what are the best Business Schools in London if I want to study Marketing Mangament or Entrepreneurship?

I would not put the LSE on that list. ESCP Europe is the other outstanding school in London.

The Imperial MSc in Strategic Marketing is a decent program.

What about for their MBA program? I don't think that LSE offers an MBA...

Imperial has a good MBA: it is fairly placed in the rankings. I don't think anyone would recommend their MBA as a marketing programme. Its elective in Analytics and Digital Marketing seems very tactical, unfortunately.