Grandmaster Yuri Averbakh:
Nezhmetdinov, ... if he had the attack, could kill anybody, including Tal. But my score against him was something like 8½–½ because I did not give him any possibility for an active game. In such cases he would immediately start to spoil his position because he was looking for complications.
I understand Nezhmetdinov is always a popular pick in these "most underrated" posts. But he was what he was...an IM, and if you kept the position quiet he didnt perfrom well.
If anyone deserves to be on this list its Sultan Khan.