is the boeing 777 the best plane for long-range flights ?

longer is a variable notion of TIME. It not only depends on the range of the aircraft but also on winds, payload, speed, weather.

but as for range, as in distance:

as previously mentionned, the Boeing 777-200 LR has a range of 9,380 nautical miles

(17,370 km)

its closest competitor, is, the A340. coming in at just under 9,000 nautical miles.

however, the 777 is generally considered, especially by airlines to be more efficient than the 340.

a simple verification: 777 has 2 engines, 340-500 has 4. 777 goes further and carries only 12 passengers less than the 340-500. (typical 3 class seating for both)

so i guess cost-wise, the 777 is the better plane to use for long flights.(and comfort wise, the 777 is quieter than the 340)

The 777-200LR has a maximum range of 9,380 nautical miles. The closest competitor to that is the Airbus A340-500, which rings in at 9,000nm.

The only airline taking advantage of that type of range is Singapore Airlines, who has a scheduled non-stop flight between Singapore and New York using the A340-500.

It will no longer be about range but time. Hypersonic cruisers would be the next thing with suborbital flights.

It Will be until the 787 comes out

To put it short, yes. Its cheaper to run then the A345, flies further with more weight and more passengers.