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Awesome Combat Flight Cockpit for Cheap
By an Amazon.com customer
Saitek X52 Flight Control SystemSaitek X52 Flight Control System
Buy new: $87.41 / Used from: $66.99
This is a solid HOTAS joystick. It's well supported, and usually you can find joystick profiles for most sims (meaning, you don't have to do all the set up yourself).
Logitech Flight System G940 Force Feedback JoystickLogitech Flight System G940 Force Feedback Joystick
Buy new: $285.83
I have no direct experience with the G940, but despite the high price tag, it does have a lot of things going for it - notably, force feedback - something unique to this product. It comes with rudders.
CH Products Pro Pedals USB Flight Simulator Pedals ( 300-111 )CH Products Pro Pedals USB Flight Simulator Pedals ( 300-111 )
Buy new: $100.18 / Used from: $200.00
Rudders add a lot to the flight experience. They make flying easier and help get your opponent into your gun sights. I use CH Pro Pedals (USB), and think the world of them, They are sturdy, stable, and are easy to setup. I recommend them.
Saitek Pro Flight Rudder PedalsSaitek Pro Flight Rudder Pedals
Buy new: $106.81 / Used from: $90.00
Another option are Saitek Pro Flight Rudders. While I tend to use Saitek HOTAS sticks, I decided not go with these because I had read many mixed reviews about them. Some people love them, some people hate them.
Naturalpoint Trackir 4: Pro By ErgoguysNaturalpoint Trackir 4: Pro By Ergoguys
Using a small infrared camera that tracks the motion of your head, you can look around your cockpit without resorting to using keystrokes or a mouse. Essential gear, this really makes the game seem real. A list of compatible games can be found here: http://www.naturalpoint.com/trackir/03-enhanced-games/enhanced-games-all.html
TrackIr 5 Professional Premium Head Tracking for GamingTrackIr 5 Professional Premium Head Tracking for Gaming
This is the latest version of the TrackIR. Even better tracking, apparently. (There are demo videos on Youtube.com - have a look!)
Logitech Trackman Marble MouseLogitech Trackman Marble Mouse
Buy new: $30.48
Why a trackball? Well, you're going to have to navigate the software's menus to get your sim started. If you built a PACS cockpit, the marble mouse is slim enough to fit behind your joystick, making it easy to navigate the menus, and out of the way when you're actually in the air.
Wings Over Europe: Cold War Gone HotWings Over Europe: Cold War Gone Hot
Buy new: $10.79 / Used from: $8.00
The Wings Over Series are great for the entry level flight sim enthusiast, although I would recommend going to Thirdwire.com and purchasing their direct downloads: the Wings Over series evolved into the Strike Fighters 2 series.
Wings Over VietnamWings Over Vietnam
Buy used from: $6.99
Another "Wings Over" title (an updated version available from Thirdwire as Strike Fighters 2 Vietnam). I play this one a lot. It's worth noting that Thirdwire also produces First Eagles, a fantastic WWI biplane simulator. I recommend that too.
Falcon 4.0: Allied ForceFalcon 4.0: Allied Force
Buy new: $27.47 / Used from: $9.39
While the previous sims listed are fun, for super realism, Falcon is the one. Be warned, there is a steep learning curve on this one.
Crimson Skies (Jewel Case)Crimson Skies (Jewel Case)
Buy new: $9.99 / Used from: $2.64
Realistic? Hardly. Compatible with the TrackIR system? No. I'm including this title because it's just plain fun. A cross between aviation and 1940s pulp novels, it's a kick to play it. You'll feel like the Indiana Jones of the Sky. Even non-flight sim folks like this game. And it's cheap too.
Combat Flight SimulatorCombat Flight Simulator
Buy new: $70.94 / Used from: $5.49
Microsoft, while not my absolute favorite company on earth, does produce some really solid flight sims. The combat Flight series is a little dated, but well worth playing. Occasionally you'll see these titles for ridiculously huge prices - don't fall for it - you shouldn't pay more that $10 for these ever.
Microsoft Combat Flight Simulator 2:  Pacific TheaterMicrosoft Combat Flight Simulator 2: Pacific Theater
Buy new: $116.94 / Used from: $28.00
The rule of ridiculous prices also applies here. (I've seen this title in Target in the bargain software section for $10) This title is not TrackIR compatible.
Combat Flight Simulator 3Combat Flight Simulator 3
Buy new: $9.82
This title is TOTALLY TrackIR compatible.
IL-2 Sturmovik: 1946IL-2 Sturmovik: 1946
Buy new: $29.99
Sturmovik covers aircraft from World War II, and includes some models that didn't go into production due to the end of the war. This is a great sim full of vintage planes.
Microsoft Flight Simulator 2004: A Century of FlightMicrosoft Flight Simulator 2004: A Century of Flight
Buy new: $20.89 / Used from: $9.95
Not a combat sim, but very realistic. A great many planes to fly, including 9 historic models (like the Wright Flyer and the Spirit of St. Louis). One of the features is "The Learning Center," which acts as a sort of flight school; there are lessons available, and it also acts as a super help system. Which is great. Loads of add-ons available. I recommend Abacus.com