A380
I am also starting on the 777 (in August) and it didn't take me too much trouble to come up with the following list of destinations (of course we will get the minimum rest Newarks, Philadelphias and Washingtons!)
From LHR :
MONTREAL
TORONTO
BALTIMORE
BOSTON
CHICAGO
DENVER
DETROIT
JFK
EWR
PHILADELPHIA
WASHINGTON
LUANDA
CAIRO
ABUJA
HARARE
BAHRAIN
KUWAIT
MUSCAT
DOHA
ABU DHABI
DUBAI
DHAKA
CALCUTTA
ISLAMABAD
BEIJING
SHANGHAI
From LGW :
BERMUDA
ATLANTA
DALLAS
HOUSTON
ORLANDO
TAMPA
ANTIGUA
BRIDGETOWN
GRENADA
KINGSTON
ST LUCIA
TOBAGO
Best Regards