More complete meaning having a wider array of qualities (technical, physical, defensive, versatility, whatever). So yeah, U would say Gerrard has a greater variety of useful attributes than someone like Zizou despite Zizou being obviously the greater player.
I say Maradona since he's regarded by most as the best ever. I obviously wasn't around to watch him, Platini and Pele, so going by what I see from video highlights, read, hear, etc., by their playing styles, I would say at least Pele (o forgive me for saying Platini) was more complete yet Maradona was better, which is why he was "carrying teams single-handedly to win titles against better and wealthier teams, both on club and national levels".
So Messi could be "the Maradona" and Ronaldo could be "the Pele".
What now?