Subsistnce farming led to terrible famine in the cities which were rapidly expanding - both the Tsars and Lenin could do little to combat this. I do not say that Stalin was necessarily 'good', but I don't think he was all bad either. I do not see any way that Russia would have become the power it did under the leadership of people not willing to employ the ruthless and brutal methods of Stalin.
Two main reasons for this I think
1 - Stalin was on our side during the war (by default, he had signed a non aggression pact with Hitler which Hitler conned him on and invaded anyway)
2 - Hitler victimised one section of society, the Jews. Whilst Stalin did have a thing for victimising certain groups as well he was more general in his approach. Also Stalin didn't write an iconic book full of race hate, Hitler did.
In Western societies like ours there is a large Jewish community including people who had relative directly affected by teh Holocaust, whereas you don't find nearly as many people over here with direct family experiences of Stalins purges, so we are more aware of it here.
I have a t shirt with the communist hammer and sickle on which I wear out and about sometimes and nobody bats an eyelid. I wonder how they would feel if I had a swastika t-shirt (especially given that I have a skinhead)
I imagine it was because Hitler was murdering to eradicate a race of people, while Stalin was killing indisciminately.
I am not saying that Stalin was good - he just has a few points in his favour. Similarly, although Hitler's own form of governemnt was highly inefficient - giving contradictory verbal orders to his juniors to spark rivalry and competition - and many of his policies were immoral, he too did manage to achieve many things.
I would say Stalin is more accepted in the UK due to
a) Lack of education compared to Nazi Germany - less press coverge, not done in school etc (The first time I was officially taught about Stalin in state education when I was doing my A levels)
b) Stalin essentially won the war for us. If Russia was not in WW2, we would have had a much greater chance of losing, even with America's support. Hitler's worst decision as dictator was to invade Russia thus opening himself up on two fronts. So I think theres an element of that, he was our ally in WW2.
c) Kind of links up with A) - the Holodamur is no where near as well known as the Holocaust - again due to lack of education. A very interesting book/film to watch which kind of explores this possibility - Fatherland. In that book (i've only watched the drama adaptation however) Germany essentially wins the war, and the Holocaust is swept under the carpet, and Stalin's Holodamur is more famous and widely known. This kind of illustrates my point.
d) The proximity of Germany to the UK. Germany is and was very similar to the UK and has strong links with the UK in history, Russia on the other hand is a lot more remote and is completely different to the UK. Germany is only an hour ahead for example. Thats why I personally find Nazi Germany far more interesting than Stalin's Russia, because it could have been us, our far right parties were on the increase at the time, and in fact only reduced in popularity during and in the aftermath of WW2. They also served a far bigger threat to us, I know the Cold War was in existence with Russia as well, however that was more of a theoretical threat, invasion of the UK by germany was a very real possibility.
I'm not defending Stalin, he killed more people than Hitler in camps, but as I said I think these reasons go a long way to explain why Hitler is often seen as more "evil" than Stalin.
Not quite sure why Russia would put Stalin in their greatest 10 people, again maybe because he won the War and prevented Russia from being ruled by the Germans, who would have been much worse on the Russians. Also the fall of communism is also a relatively recent event in Russia, and Russia has struggled a bit since the fall of communism.
Interesting topic non-the-less.