My bro and I are thinking about spending about two weeks in Europe. I'd love any advice to people who have been and what to see in the cities we're planning on seeing. We've already been to Spain, Italy, Greece, and Turkey.

Our plan

UK
-London

France
-Paris
-Lyon

Germany
-Munich
-Berlin

Netherlands
-Amsterdam

The thing I fear is this might be too much for a two week trip so the second city mentioned in some countries are currently planned but can be removed (not too sure about Munich vs Berlin though).

Ideas, advice, etc?