I think it simply has to do with some shows being more influential than others. Dejiko was the face of Akiba for many years, Rozen Maiden had (still has?) yearly festivals, Haruhi defined a genre and is the queen of /h/ here.

As for the anime you counted, there are multiple threads about them, but there are less chances to refer to them in usual discussions. If you are interested in discussing specific anime, you also shouldn't be shy to use our Anime board - you are likely to find some other interested people eventually