Game: Conker's Bad Fur Day
What Makes Them Bad: Making Conker's world go to sh...well, you get the picture.
What Makes Them Cool: How many times have you seen a talking piece of excrement in video games? 

He may be little more than an enormous dump, but the Great Mighty Poo of Conker's Bad Fur Day is the most disgusting menace most gamers can honestly claim to have ever seen. He's also an opera fan, bringing about his own demise by singing in too high of an octave. Way to go, Poo.