cosmos 1000 has best sound baffling but also the worst thermal performance.
the haf 932 is next quietest but frankly, the fans are pathetic
the antec 1200 and sniper storm are on par with respect to cooling performance and both provide fans controls that allow you to dial it down for quietness. I would give the edge to the storm as the larger 200mm fans are better at lower RPM but the antec 1200 comes with more fans as part of the package.
the sniper is far lighter and easier to move than the extremely heavy 1200 though. very important to me as I upgrade frequently and hefting the 1200 was becoming a real chore.
I do like the black interior of the 1200 although its tiny window makes it moot. One thing about black interiors is that they scratch easily. the sniper has anodized steel (as opposed to the regular ugly grey SECC typically used in the HAF) and no window so black interior is irrelevant.