Lock On and Falcon are both excellent sims and backed up with an excellent community.
Falcon 4.0 is noted for being very realistic by the actual Falcon fighter pilots that play it. The patches that the community have made for it are a must. I have owned this game for years and while it *is* terribly complicated, it is a lot of fun for the challenge alone. In addition to flying, you have to worry about the radar scan patterns and heat seeking missle head coolant levels for crying out loud!
I have not played Lock-On myself, but have heard many great things about it.
If you are truly psycho, you can purchase TrackIR 3 to enable your head movements to change your in-cockpit view in 6 vectors.
www.trackir.com