I use a CH USB setup (stick, throttle and pedals). I recommend a Combatstick 568, which offers a larger base and stronger springs.
Much has been said about CH gear, so I'll offer another alternative. For the new player, to avoid a major investment before knowing how serious you'll get about these types of games. You can make due with two inexpensive joysticks. I recommend USB type sticks for smooth operation.
One stick is used for flight control (the right hand stick for right handed people). This can be any stick of your choosing with an assortment of buttons and hat switches. The buttons should be located on the stick instead of the base. A built in throttle is not required.
The other stick can be simple, with buttons as available. But it must have axis switches to disable the centering springs, a seperate switch for each axis. (If one cannot be found, a person could open it up and disable the Y centering spring.)
The Y axis (the up/down motion) centering spring is switched off to stay where you place it, so it can be used as a throttle.
The X axis (sideways motion) centering spring is left engaged, so it will return to center. This axis is used for your rudder.
For many, this will work fine for a permament setup, and your cost $50 or less.