RE: B777
I flew my first 777 with BA in January LHR to NRT.
It was pretty impressive, a very smooth flight with comfy seats and almost seamless take off and touch down.
The 747-400 return flight was just as good but probably edged it due to getting one of the window economy seats at the very back where the fuselage narrows. This meant it was a row of two seats and not three so could stretch my legs down the side for 13 hours.
Plenty of nice freebie snacks on both legs including pot noodles on the return!
A340 remains my favourite wide-body to date though. Flew Air France CDG – BKK return in 1999 which was superb. I was even able to have a couple of cigarettes in the galley areas!