I'm a big fan of
Lethal Skies and
Lethal Skies II despite their so-so review.
The games are broadly similar to Ace Combat (console-firendly controls and a lot of boss battles against huge vehicles) but have more realistic features like the fact your plane's missile capacity is more limited, damage on individual components of the plane having effects on the plane's performance, and the option to enable black outs/red outs (they're more "realistic" than Ace Combat, but all that said, they're still "arcade" games more than they're simulations). Rather than taking the Ace Combat of having you and useless wingmans take on a large number of stupid enemies in long missions, Lethal Skies has you and a number of competent allies fight in short missions against enemies who are small in number, but stronger and smarter than your average flight game enemy. You can also customize your loadout with different types of missiles (with each airplane having different number and type of pilons to mount weapons on), Indeed, figuring out your favourite weapon loadout for a given mission is part of the fun. Also while the plane roster is comparatively small (13 in the first, 19 in the sequel), they feel much more differentiated than other console air combat games, where planes are mostly a succession of bigger sticks.
Lethal Skies 2 is largely more of the same, but better. The boss battle aspect has taken a backseat (though its still there) but the regular missions have gotten more scenarized and creative. One early in the game puts a twist on the cliché canyon run mission by having you land in the middle of an enemy base to pick up a secret agent. Another has you destroy defenses around a castle and then make use of the planes VTOL capabilities to land inside a small courtyard and blow open a gate.
Also one of the plane unlockable in LSII is a VTOL version of the SU-47, which is hilarious and awesome.
Another good cheapie is
Airforce Delta Strike. That game is more similar to Ace Combat and it's all excess - wheter it's the insane number of planes and missions, the ridiculously anime story, the hammy voice acting by 4Kids actors, or the craziness of the mission themselves. In one mission, you must dive into the vortex of tornados to destroy weather control machines. In another,
you fly your jet inside a metro. The campaign lets you choose between multiple characters, including a crazy old man who only flies WWII-era planes. It's kind of insane, is what I'm saying.
The gameplay itself isn't as good as Ace Combat, because of the lower framerate, padding, often rough graphics and difficulty spikes. But it's worth playing, and like all the games I mention in this post, it's cheap on the secondary market.
Aero Elite: Combat Academy is a great attempt to do a proper (but still approachable) simulation on consoles.
Though not about flying,
Sub-Rebellion hits some of the same beats, albeit with a more relaxed pacing and more exploration elements.
I've yet to play them, but
Skygunner (a bit pricy that one, though),
Dropship: United Peace Force and
Sky Odyssey are all flight games on the PS2 with cult following.
I also like the two
Star Wars Starfighters and
Battlestar Galactica, but they'Re much better played on original Xbox if you have that.