The only answer now is both. Anyone who says one is much better than the other simply doesn't understand the other game. Can you like one over the other by a significant margin? Of course. But they are both great games.
And what do they have in common? John Borg and Lyman F'ing Sheats. There is magic in that combination. It may not be there at first... in fact for both games they started a bit bad. But Lyman can grind out a game and turn it into magic. And in both of these cases, he did.