- The Master from Fallout 1.
*Possible spoilers*
He has an interesting storyline and has had quite an impact on the Fallout universe and a very important character in general (he created Super Mutants). What I also liked about him is that his finals goals aren't necessarily "evil" or "bad", it's just the way he's going to go about, basically "the ends justify the means". He intends to eradicate all of the negative aspects of humanity such as greed and racism forever by getting rid of it's source...humans.
Oh, and of course he has a very unique...errr...."appearance".
- General Oliver in Fallout: New Vegas.
He's a power hungry, thick-headed lacky that doesn't know how to properly run an army or use military tactics. But he's just so damn well written and funny, and his voice is really good too, not to mention his uniform.