Best Deal for London Hotel?
The Sheraton Park Lane has renovated rooms (not all yet) and I liked my king room (review on my blog philatravelgirl)
If small room is ok, check out the many Z Hotels - I did a site visit at the Soho location http://philatravelgirl.com/london_for_less_z_hotel_soho/
Other options The Hoxton or Citizen M or Club Quarters