yea the t-34, and what i find funny is how people seem to forget how revolutionary it was, i overnight made EVERY german tank obsolete, in response, many german generals simply wonted to copy it, they did not know what to do, if it were not for horrible crew training, and idiot generals, (stalin killed 2/3's of his generals in the thirties) they were world beaters.
They finally responded in the 1942-3, with the tiger and panther respectifully, these were great tanks but were overly complicated and expansive. The germans have a habit of over complicating things, ex. german cars. When not in the shop being repaired, they were exstremely effective, but the numbers were also inflated by the superior crews and tactics of the germans. A good tank crew is worth more then a good tank. look at the merkeva