^Actually, Black Ops on Veteran isn't tough. As long as you just sit behind crates and let the NPCs kill each other, and run away when it's a good time.
I feel like Homefront on Veteran is worse though, because the enemies will only shoot at you, and your team doesn't help at all.
Hardest game to date though, is probably The Elder Scrolls: Oblivion. If you don't look up on the internet where to get all the good weapons like my little brother did, then it's a huge pain to do anything inside the Oblivion Gates.