I have to disagree with a lot of these picks, because a lot of the times I find that blandness can be just as identifiable as something tacking and flashy like DSquared2's blatant A&F rip-off look.
For instance, Calvin Klein. To me these looks are total signature Calvin Klein, although with some definite similarities to what Prada was doing back around 1997 (esp. in the first one with Gemma...)
(from style.com)
And I find this even more so with the last seven or so Ghesquiere Balenciaga collections, because there are so many signature ideas he has been working with:
-cropped jackets that bulge out in the upper portion near the shoulders most likely with a lot of buttons
-navy/military pieces in a highly refined, tailored fashion
-the very high-waisted cut of his pants (Chloe did this prominently for one season, but with Balenciaga it has been consistent for a long time)
-the scuba, underwater ocean-life prints, electro-yellow neoprene theme stuff
-futuristic, architecture-inspired tailoring, especially in larger coats
-not to mention the one off collections that become very recognizable like the patch-work with army green cargo pants (S/S 02)
Anyway, just my thoughts. I tend to find stuff very easy to recognize when a designer sticks with some basic silhouettes or themes throughout most of their collections. It's part of the reason why I find Simons, Slimane (those small collars and skinny pants alone,) Helmut Lang, Ann Demeulemeester, Marni, etc so distinctive and easy to spot!