Should I trade in Gears of War 2 and Far Cry 2 for Fallout 3 or some other new release OR COD 4?

I DONT play gow 2 online i just dont like it much and i played the singleplayer mission twice. far cry 2 i haven't finished but it doesn't look like i'll miss it. So should i? they add up to 70$ at eb just enough to buy a new game.