Commissars House.
I always seem to have good games there, I love how the actual Commissars building is split into two capture points as well, despite being the same building. Makes for some really fun firefights when the Germans are pushed.
I would put Grain up there too, but I've found it to be increibly frustrating once you get into the main building. Alot of players don't seem to 'get' that map, and like to just run around mindlessly not contributing to the objectives. That will probably change as the slow players get used to the map though, its definately one of the more complicated scenarios.