Either Mass Effect, Ace Combat or Final Fantasy.
Even though I am yet to play ME 1, I was very impressed by it's sequel, story-wise and gameplay-wise. I have no doubt that ME3 is going to be something epic.
Ace Combat is THE best jet fighter combat of all time. What makes the games so special is that is brings the traditional and very impressive story telling of the japanese and combines it with epic jet fighter battles. Like Metal Gear Solid but you're a pilot instead.
The Final Fantasy series has to be my all time favourite. I have 7 of the 13 games and each one of them is mindblowing in their own ways. Obviously japanese story telling sells the series but the gameplay over the last decade or so gets ever more impressive. Overall the series has been very consistent in providing very impressive games and the amount of ideas they have is seemingly endless. My favourite games have to be FFVII, FFX-2 and FFXIII.
