haha yeah thats what I would say. If ya got the money now ya might as well get GoW. There is no point in waiting for Halo 3, by that time you can just have both.
I assume you mean Call of Duty 3. If you've played Call of Duty 2, it's the same game basically with new misisons. Gears of War is more interesting. But if you don't have someone to co-op with or multiplayer with, I'd get COD3. Gears of War is definitely meant for multiple people. More fun that wya.