There are a number of reasons why
Stalingrad is still to this day a very famous battle that took place in WW2. It was crucial in stretching the Germans to breaking point, the Russians clung on to the city
from the river side by pouring troops into a virtually ruined city. Hitler dug his heels in against his top military peoples advice; they would not leave Stalingrad until the bitter end and ultimately defeat. Books, movies have recorded how Stalingrad played out and enlighted the public of the seige!
Two things that are associated with Stalingrad are Snipers and the cold weather. The city had so many snipers on both sides dug in movement around the buildings was almost impossible. Much of the movement was done at night or in tunnels under the ruined buildings. The weather meant many troops on both sides suffered, inadequet shelter, clothing and rations meant it was hell on earth, especially as the battle lasted for what seemed years.
The Germans initially had huge numbers in Stalingrad, over time the sheer amount of troops they needed to send there to keep pushing the Russians back came at a huge price and at the expense of weakening them on the Western front. The Russians had what is seemed millions of recruits to fill in the now growing death toll (1 million Russians died in Stalingrad with over 13,000 shot for deserting). Men, women and young boys it didn't matter the 'Zerg' was all important and in the end proved a key factor. The photo shows 62nd Stalingrad Army marching in Odessa.
