Falcon 4
I've got both Allied Force and the original F4+Open Falcon installed, even though Allied Force sees much more action thanks to the added avionics in OF that I haven't bothered to learn yet
The F16 is indeed a pretty complicated bird to master. In my opinion it is also a good looking sim if one cranks the graphics up to the maximum. As UberGeek said above the dynamic campaign is also one thing definitely worth checking.