I would add the Ampersand to this list, which is a bigger sized hotel with good public areas. Not seem a room. Opp SKen tube.

The Crowne Plaza, oddly, is very nice post refurb and some good duplex suites which overlook the huge hidden garden at the back.

The Belmond in Chelsea should open in January after a total refurb. Modest stroll to South Ken station.

if you get a map out, you will see that the Mandarin Oriental is only about 10 mins walk to South Ken station too although technically Knightsbridge. You could then start adding Jumeirah Carlton Tower, Park Tower etc.