You are right about there not being a great deal of good simulators being made, but there are a few developers who keep pushing the boundaries. Thunder Works is one of six companies I can think of that create, or are attempting to create, simulators with complex and realistic flight models (Microsoft, obviously, is not on that list, and neither is Jane's Combat Simulations).
Whenever you realize it or not, in a few years it's quite possible that the technology used in Jet Thunder and the other simulators of this generation will be surpassed by technology developed by companies such as Gennadich, Eagle Dynamics, and Hitech. I would put 1C Maddox Games and Xtreme Simulations International on the list, but they've always been a bit behind (especially 1C Maddox Games, who have always insisted upon using a hilariously antiquated engine with severe limitations instead of making a new one).
And then there is Laminar Research's X-Plane, which is extremely innovative as far as flight models are concerned. However, that's not a combat simulator, and the rest of the simulator is quite dated (such as the graphics and damage model).
