I just finished Ace combat 6 for the 5th time, on the "Ace" level.
Normally I'd be crying and weeping on the floor but since you get the uber-rigged CFA-44 Nosferatu (just a hint, it fires 12 missiles at time, and has an instant kill railgun, not to mention it handles amazingly well) it is EXTREMELY easy.
Seriously, I passed the first 6-7 missions alone in barely two hours with the Nosferatu.
The graphics are awesome, the destruction of a fighter by machine gun fire is satisfying and the story isn't just about killing everything.
EDIT: Oh, and the sci-fi superweapons are epic.
EDIT2: Also, once you get the hang of machine gun firing it becomes a lot easier, and a lot more awesome. Just align your sight so the machine gun crosshair (little circle thingy) is right on the enemy airplane and start firing away.
Crimskon Skies is still the best aerial fighting game ever though.