Ah, Flight Unlimited. Truly, the only limit to the flights here are how long you're willing to keep respawing. There's something charming about the simplistic way it renders the land; which was innovative at the time, yet so quaint today.
This flight simulator has a few unique qualities; the lesson mode especially teaches you about many stunt flight tricks such as the hammer turn, Aileron roll, and even should you actually choose to do it, landing. The inbuilt flight recorder as well is unique, letting you break off from the recording at any time and begin flying under full control anytime.
Most of all though, is the pedigree of Looking Glass Studios, who put their typical prestige upon the game, with a good amount of silliness around the Flight Offices.