Tom Clancy's HAWX is one of the more enjoyable flight combat games available on this generation of consoles (and PC). The flight system is tight and intuitive for first-timers and the advanced system gives an extra level of control for advanced users, including a drift turn system that has no basis in reality but is very enjoyable. The campaign is a decent length without dragging on, missions are varied enough to keep your attention and the persistant leveling system that carries over from single player to multiplayer gives extra motivation to go back and get more points in each mission.
Bottom line:
At launch this game was a must-buy for flight enthusiasts. Now, with sub-$20 pricing there is no reason to pass by such an enjoyable title.