Recently I stumbled upon the updated Strike Fighters 2 series of "light" flight sims:http://www.thirdwire.com/index.htm
I remember reading reviews of the original "Strike Fighters Project 1" a few years back, which was promising but had some shortcomings. Now there's an upgraded engine, most gameplay bugs have been ironed out and there are now half a dozen games based on the same engine. The games are fully moddable and they can even be merged into one installation.
I've started with SF2: Vietnam, since is features the F-100D, F-105, F-4, F-8, A-4 and A7... all awesome planes that don't get much love in other sims, and so far I'm having a blast. The flight model is of course not on par with something like Flanker 2.0 or Falcon 4.0, but it's convincing enough and the different planes each have their unique handling quirks. Operating the primitive radars and bombing without CCIP is also challenging but lots of fun and makes you really appreciate the A-7 for having the first "modern" HUD. My only real complaint so far is that carrier ops are crudely implemented, there are no arresting wires... the planes just slow down when touching the deck like it was adhesive, but that might be improved in future patches.
There's also a damage system that (for most parts) realistically influences the flight model.
For example, in a simple single mission me and my wingman took on a pair of Frescos. I send my wingman after one MiG-17 and engage the other one, trying to get into position to get a lock for my Sidewinder. As I struggle to get behind my MiG-17 I hear my wingman screaming in panic over the radio and realize that getting into a turning fight with Frescos while sitting in a Phantom... that thing bleeds airspeed like crazy in tight turns (the ability to hit the burners and climb out of hairy situations is awesome though).
So, as I hear the death scream of my wingman I realize that I will soon have the second Fresco on my tail while I'm still trying to shoot down the one in front of me. And soon enough i see tracer rounds fly past me from behind and shortly afterwards I hear the "CLUNK CLUNK CLUNK" of bullets entering my plane... but she's still holding together. Finally I hear the higher-pitch growling of my Sidewinder seeker having locked on and I blow the Fresco in front of me out of the sky and turn sharp to shake off the other Fresco behind me. After another intense 30 seconds I send the second Fresco to the ground, the whole time wondering why my F-4 is swinging so violently from side to side when turning.... only when switching to external view things became clear, she was still fit enough to limp back to base though.
So, anybody else got some opinions on the other games? I'm thinking about getting SF2: Europe next... mostly because of the Harrier and the A-10, plus the fictional campaigns of the evil Sovjets invading western Europe sound like fun.