To clarify a point of possible confusion... the 'Sheraton New Delhi' is actually located in the very south of the city. The Maurya (ITC) is located near all the diplomatic posts (in the nice part of the city), though not exactly in walking distance to anything. The LM is probably in the best location if you want things in walking distance, like the major tourist attractions. That assumes you're willing to walk around in the crazy Delhi summer heat :P