I would have to say that the best plane over-all is the 747-400 for first and business. The other 747 come right after that, followed by the 777.

It is just that United First on the 777 does not recline far enough.

The 767 is simply to narrow, although tolerable.

I guess I will be the only one to defend the DC-10 (but only in two-class config. when flying first - to Hawaii). It is nice to sit in row 1C & D, as both people have aisle seats and plenty of leg-room (Only draw back, so much leg-room some passangers consider it a place to cross-over from aisle to aisle, but a few nasty looks and they get the hint!!)