What about mouse and keyboard? Since it's farfar away from a flight sim I see no point in using a joy. But since you asked; I use the saitek X52 for my flight sims. There is no real alternative to this stick at the moment.
I switch to joystick whenever I pilot helos or aircraft in BF2. To me it's just easier. I never could figure out how to fly or hoover with keyboard/mouse without crashing. As a pilot and a fan of flight sims, I find using a joystick much more natural. The BF2 flight models are another debate entirely.
By the way, I use the Logitech Extreme series. They are pretty good low to mid-grade sticks.
Back when the game first came out and I played on my friends computer, we both found it easier to pilot with a joystick. I used the Saitek Cyborg Evo and it works like a charm. I used the X45 for a while but I didn't like it so I sold it.