the games aren't that bad, and bo3 looks pretty fun if they get it right
bo2 was basically bo1 with more "futuristic weapons" and gameplay was barely changed aside from "advanced gui"
bo1 was great, bo2 was a repeat of 1 with small changes
if i had to say any of them were the best of the franchise, it'd be 4 and 5 (CoD 4: MW, and CoD: WaW)