The trendy, young and designed hotel chain Citizen M is originally from the Netherlands (where the head office is located) and has branches in London (Bank Side) Amsterdam, Glasgow and soon to be opened in New York.
The philosophy of the hotel is "affordable luxury for the people," and indeed, the price range is less than 200 British pounds per night. The rooms are quite compact, but that's OK. The lobby and common area are quite big, and easily serve as your living room where you can hang out with friends.
The hotel has various designed meeting rooms, working space, and so many shelves filled with a great collection of art, fashion, travel and photography books. The atmosphere is very friendly and easygoing, which makes your working time even more enjoyable. I know where I'll book my room during my next visit to London.