War of the Rats

For a fictional account of the battle of Stalingrad, you can't make a better choice than War of the Rats by David Robbins. While the book is categorized as fiction, it is heavily based on documented fact. After you have finished reading the book you will literally feel dirty, almost as if you had been living in the rubble alongside the characters.
The primary focus of War of the Rats is the legendary and true sniper duel that took place between Vasily Zaitsev, the head of the Russian sniper school, and Heinz Thorvald, his German counterpart. Zaitsev was so successful at introducing the cult of sniperism, and such a major personality on the Russian side, that the Germans felt the need to eliminate him for propaganda purposes. Russian snipers, trained by Zaitsev and others, had killed literally thousands of Germans. They hunted singly and in pairs through the ruins of the city, often waiting in hiding for hours or days to take their shot. Morale on the German side had plummeted as a result. If they could manage to kill Zaitsev, it would give a boost to the average Wehrmacht soldier.
The deadly chess match that took place between these two men went on for four days. When it ended, only one of them crawled away. You'll have to read this excellent book to see which one.