I have a stash of flight simulators from warplanes to civil and commercial simulators.
The best flight simulator I have ever played for realism/authenticity and the like was Janes WW2 fighters, sadly an old title now.
There is a developer that specialise in releasing titles which solely focus on a particular plane, the realism is outstanding, graphics are solid but the downside is that you can only play with that particular plane, they have; P-51,P-47, Spitefire, etc in the title.
MS combat Flight sims are good, notably 3.
Lock On if you have the patience is a good modern combat simulator...............I must warn you that it is extremely difficult to come to grips with.
FSX if youve got an i5 Prcessor or above or FS2004 if you have below
lulz... dont be daft fsx runs on any system from 1 to 12 cores...
as far as i know it only uses a single core so the faster the cpu the better... preferably 3.0+ghz
i dont have an i5 2500k but can play fsx just fine, not that i would as its pure boredom on a disk.
Windows XP SP2 / Windows Vista / Windows 7
Processor: 1.0 Ghz
RAM: Windows XP SP2 - 256MB, Windows Vista – 512MB
Hard Drive: 14GB
Video Card: 32MB DirectX 9 compatible
Other: DX9 hardware compatibility and audio board with speakers and/or headphones
Online/Multiplayer Requirements: 56.6 kbps or better for online play
official recommended specs... the reason people think you need high end is because the game is limited to 20 fps by some dlc and make an assumption that there hardware inst up to scratch when they see fraps throwing out low fps... maybe they should have read the instruction manual first and it would save confusion...