Black Ops.
Honestly, for as many people that bought it, and as many people that still play it, I'm surprised. Sure, it can be fun at times. Like, if you're screwing around on multiplayer with the crossbow and tomahawk. Other than that, the single player campaign is horrible (I couldn't finish it. It drove me insane how straight up bad the level layout was, how boring the campaign in general was, and how crappy the enemies were as a rule. The only level I thought was even slightly cool was the Soyuz launch, and the end to that was more than a little bit unrealistic). And the infinite spawns were rather annoying. Seriously, since when is it possible to fit 127 men in to a shack the size of my bathroom? Did the Russians start using clowns as cannon fodder?
On to the multiplayer. To start, the weapons were crap. Much like World At War's weapons, the best ones are only gotten late in the leveling up, and there's extremely little motivation to prestige. Not only that, but the levels are, yet again, crappy. There isn't a single one that I can say I look forward to playing, and most of them I severely dislike. I pride myself in being accurate, which means that I typically use single-shot weapons and snipers. However, snipers are completely useless in all of the levels, and the way they handle makes using them for short-range sniping (no, not quick scoping) neigh impossible. The semi-auto weapons in the game are also extremely poorly designed. Seriously, the AK-47 is more accurate than the M14, and the Commando more accurate than both of them, and snipers are about on par with the ballistic knife. Am I the only one that finds that nonsensical?
Overall, I'm sad I wasted $60 on the game. I would've paid $30 for it, but if I'd known how bad it was beforehand I wouldn't have bothered. Definitely the worst game that everyone played.