I think you should read my reply in 'What are tanks?' to that.
In 1941 Russias tanks certainly were not good, going from a force of 28,800 to 1506 surely shows it. Their production was their greatness and the German tanks were still better on paper. The reasons the Germans lost was not because of their inferior tanks, it was because of their inferior numbers.
German tanks were the best of the war, if you are want to average it out. Early war, 1939 - 1940 Britain were the best, only because of the Matilda, 1941-1942 Russia were the best, 1943 onwards Germany were the best. All the way through Germany were only slightly surpassed.
The Panzer IVG always matched the T-34 of any variant, and the Panther walked all over the T-34 in combat until it was overrun by many T-34s. In one battle 7 Panthers met 70 T-34s and in the 20 minute conflict destroyed 28 T-34s without a single loss.
The Panzer V 'Panther' was the best tank of the war. And that was designed to combat the T-34, so there's something you can say about the T-34.
You do realise the T-34 would have never existed if not for the American Christie tank system, by good 'ole New Jersey man Walther Chrisite. So, this was not a Russian invention. And in fact it was the JS-3 that pioneered modern tanks and this was based off the KV more than the T-34.