Worst for me, Counter-Strike 1.6. So bad, it got me to waste 1,000+ hours playing it. Not sure how.

Haze and Duke Nukem Forever were both pretty fucking terrible but I only played the demos, not the full games.

Operation Flashpoint was one of the worst. I rented it because my buddy bought it, and it was HORRID, the online was so laggy that it was virtually unplayable, and the single player just straight sucked.

And if anyone says Medal of Honor (but thinks Battlefield is good) I'll just lol because it's the exact same game (same engine, same developers).

Possibly wrong and wrong.

Well the multiplayer mode was made by Dice and they used their Frostbite engine there. Still Battlefield 3 has a far superior multiplayer mode.

@Marks: Not quite, only the MoH (2010) MP uses the Frostbite engine, SP uses Unreal 3.

The MoH MP was developed by DICE true, but the SP was developed by Danger Close.

I'm serious here, but:

MoH SP > BF3 SP
BF3 MP > MoH MP

FAR CRY 2!!!!

I admit I've only played about 1,5h, but damn, it started SO LAME. You just drive across an empty jungle with akward controls, akward map and camera, and it's about 90% of the time. Then the car can get stuck between some rocks or something, in the middle of nowhere and you have to walk for about 10 min to get to the next town. I also died one time and had to drive to the mission again...omg

I can't even say anything about the actual shooting since I almost didn't get to it....

I reckon I'm the only person alive who actually liked Far Cry 2 :p

I knew about the online mode. The single player felt like a completely different game.

I guessed on same engine (they look the same so it must be), and DICE was in charge of the online of MoH. When we're talking shooters nobody cares about single player, it's all about the online. 

Hexen 64, do you remember that awful game?