I think Fischer was very similar to Karpov, both were very capable of winning due to seemingly 'minor' positional advantages.
Here's a very instructive game by Fischer where I sometimes get the impression that Black's game is pretty much lost due to 5...exf6?!, when White gets a longterm advantage (a pawn majority on the queenside):
So, when a player got a seemingly 'minor' positional disadvantage after a few moves in the opening, this could be sufficient for Fischer to win the game.
A similar example, a game which I admire a lot, by Karpov. Here after a few moves Black gets a 'bad' bishop, in the course of the game this 'bad' bishop gets even worse and it is amazing how Karpov finally realizes this advantage:
So again, both players, Karpov and Fischer, were really strong when they got a minor positional advantage in the opening, then they would play patiently and simplify the position to an endgame where they won.
Very similar in style. Also similar to Karpov, Petrosjan and Fischer - to some extent - is Smyslov, who was also very strong in winning due to seemingly 'minor' positional advantages. And of course Capablanca. The games of these masters are very instructive and beautiful in their very own way.
Botvinnik, in that he played the Caro. Capa, as mentioned. Some possibles stylistically: Flohr, Seirawan, Nunn, Mecking.
But I also go along with those who point out the ferocious attacking side of Petrosian & Karpov (EG Karpov vs Korchnoi, the two most Key Yugoslav Attack wins of that century vs the Dragon), in addition to their fine positional skills; when they elected to pursue attack rather than some technical advantages.