“Speak low” - an awesome cocktail bar, hidden behind a sliding bookshelf in a tiny shop called “Ocho”. There are 3 floors (too my knowledge), and you have to be invited to the next level (ask the waitress if there’s room upstairs). There are completely different drink menus on each floor. Google “speak low shanghai” for direction, it’s on the tripadvisor top 10 list, so not a very well kept secret 
Not a shabby place by any means, suit up and bring lots of cash. Drinks are in the USD20 range.