I am not quite understanding the point of this debate.
The UK has nothing to thank the USSR for, and vice-versa. Both countries were acting solely out of self-interest during WWII. Do you guys really think that either Churchill or Stalin (or Roosevelt) gave a rats ass about the Poles, the Austrians, the Czechs or the Chinese? No government went into WWII for the "good of humanity". Were there idealistic individuals who volunteered to fight? You bet. But no country, be it the UK, USA, USSR, France or whatever got in out of altruistic reasons. They went in because they were either dragged into the war or felt directly threatened and declared war on Germany.
Churchill and FDR did not send convoys through the treacherous North Atlantic infested with U-boats out of compassion towards the Russian people. They did it because it made strategic sense at the time. If it had not, they would have had no issue letting the Russian people be crushed under the tracks of the German army.
At the same token, the Russians did not endure the siege of Leningrad, held the German army at the gates of Moscow, crushed the German 6th army at Stalingrad and ultimately broke the back of the German war machine on Kursk out of their love towards the "free world".
Even the USA did not join the war out of compassion. It did so because Hitler declared war on the US right after Pearl Harbor. Had he not done that, it would have been politically impossible for FDR to send troops to fight in Europe, since at that point, most of the US public wanted nothing to do with another conflict in Europe.
Let's also remember that France and UK had no problems with Hitler in the beginning, as they saw him as a counter balance to Stalin. Later, it was the USSR's turn to have no qualms with signing the Molotov–Ribbentrop pact with Nazi Germany and split Poland between them.
There were no "good guys" during WWII, when we talk about governments. There were some governments that were arguably less brutal than others, but in the end, Hitler, Stalin, Churchill, FDR all had very little regard towards human life. They were all willing to bomb cities full of civilians into oblivion if that was what it took to accomplish their goals.
Let's restrict this "good guy X bad guy" thing to Hollywood and out of history, shall we?