Gears and not God of War deserves the acronym GOW.

[Zkuq]

God of War came out first. Besides, the franchise is popular, good (though I haven't played myself except for the PSP demo) and the acronym GoW is mostly used with God of War. Sales alone are not enough to change a meaning, especially if this single forum can't enforce the thing on other forums as well.

Oh, and even the OP called Gears of War simply Gears, which is a rather good acronym in itself. See, there's no need for another acronym.