Walther Røhl is probably the most complete driver anywhere, having won in pretty much any condition or class short of F1.
But for WRC, I'd have to say Carlos Sainz. He's amazing, that guy is still dishing it out like he did twenty years ago and towards the end of even teh wost races you can expect him to mount a massive attack on. Don't know how he does it, but somehow he's just always there at the thick end.
Of the current crop, I'd say Loeb even though I'm Norwegian and probably should say Petter
Did you see him start driving tactically as well in Finland, this does not bode well for the
Good Guy[TM] (yup, that's petter
)