a previous post I mentioned I had finished Duke Nukem Forever. Not a great game, but I dig the series humor.
Taking advantage of the Steam summer sales, I bought the expansion "The doctor who cloned me" and I recently finished it. Again mixed feelings: There are some fresh and enjoyable ideas regarding the Duke Nukem clone army that you fight, and some brilliant level design (like the portal-like scenarios where you need to pass the Duke Nukem tests) but again it´s often visually poor, and after you finish the doctor the plot totally changes in favor to another alien invasion which offers little to the game. I´m prone to suspect it was a group of levels who didn´t make it into the game, and later they were added to this DLC.
So once more, if you like the Duke Nukem persona or shooters in general I may recommend it, otherwise it´s not the game for you.