UA used to run a 777 SEA-ORD-CDG, but now the SEA-ORD segment is a 757 and then the plane changes.
If AF did fly SEA-CDG, their brand new 777-300ERs would make perfect fits.
I would love to see UA resume SEA-LHR service using a 777. Our only international flight is to NRT, so if they brought us SEA-LHR and maybe SEA-HNL-KIX on a 777, they could make better utilization of the planes.