А как же Т-35 и КВ?
At the beginning of the Great Partiotic War the Red Army possessed 639 KV-1 tanks. In 1941 the KV-1 heavy tank was able to destroy any German tank. There are some accounts when a single KV-1 tank delayed whole German armies for days.
A single KV-1 made a stand near a road not far from Ostrov (Baltic states) and delayed the whole German tank army.
http://www.battlefield.ru/kv1.html
An interesting fact is that the Germans never managed to destroy a single T-35 by themselves. The only way the T-35 could be beaten was if it broke down or ran out of petrol.
http://home.swipnet.se/tanks/history/wwii.htm