I think I mentioned Volgograd as a possibility when Assif first suggested Communist Architecture. I certainly support "Communist Architecture" as a subject - the problem is finding the "best"/right example. I looked to a Soviet city as the "home" and Volgograd came to my mind for a number of reasons
a. I was there about a year ago
b. It was completely rebuilt post WWII (apart from a number of "memorial houses")
c. The statue of Mother Russia rather appealed both in itself - as Assif says it is rather pompous - but it is rather moving too in its location on Mamayev Kurgan as part of the War Memorial. I guess the Statue of Liberty is "pompous", also though its image is always more friendly, and it provides a nice comparator. "Mother Russia" may be Stalinist and be associated with much "negativitiy" but it reflects a justified pride in country also. The statue of Liberty also has 2 sides to its image and is often used to represent what can be bad about US foreing policy etc - on reflection it was a strange choice to get inscribed - I can think of no other such overtly nationalisitc icon which has been so honoured!
The trouble with Volgograd is that it does't have that much "Stalinist" Wedding Cake type architecture. I remember the usual Railway station and the steps up from docking area. -but not much else. The rest is standard 4/5 story communist apartments along the usual avenues - of its type and era but not I think justifying inscription (We could have an "Anti-WHS" list - the worst/most naff things in the world. I always remember visiting the awfulness of Bratsk towards the end of the Soviet era and being told by our Intourist guide (a bit of a rebel in those final declining years of communism - Intourist guides in earlier years would never have spoken so negatively) - "Now you have seen the real Soviet Union"!! Barentsburg in Svalbard has a similar atmosphere and no doubt there are others in the further reaches of the old USSR - along the BAM for instance!)
If this type of Architecture is to be nominated there doesn't seem to be any argument that the largest number and the biggest egs are, as would be expected, in Moscow. Minsk has some and Assif mentions Warsaw - but these are just "oddments". This Wiki has some fine photos of Moscow's http://en.wikipedia.org/wiki/Stalinist_architecture
Although we have already identified the moscow Metro I think the Stalinist Architecture must come from there too. Perhaps the 2 should be linked under a common "The Soviet Architecture of Moscow" (only a couple of metro stations and perhaps 3 or 4 Wedding cake buildings)??