For an evil character I'd want a large, intimidating German Shepard. For a good guy I'd want a Husky.
Good dog: Cici (Comes from CC, an abbreviation of "Canine Companion") or Dawg.
Evil dog: Goebbels (Because he'd be a German Shepard and I have a sick sense of humor like that) or Fluffers McPuppykins.