2. Fallout 3
Thirst Level: 9.98
Dave's thirst is so uncontrollable that he has two wives. His reason? To "re-populate the land of Dave so they could grow and soon own all of the Capital Wasteland," as Dave's first wife, Rosie, puts it. And judging by how many children he has (six) this excuse seems believable. But the guy definitely sounds like he has his head up his ass.
A town named after himself, two wives and a community that treats him more like a deity than a president, Dave's thirst for power is almost as strong as his thirst for, well...you know.