Virgin Atlantic can get you seats in economy for 6k each way or in business too. Also good for Long Delta/West Jet Flights.
That is it but fuel surcharges also have a huge factor. Also you can transfer to Hilton right now at a 1:2.1 ratio. Normal AMEX ratio is 1:2.
This is 2.19cpp. No need for comments as I covered most of the sweet spots.