Not necessarily. Studio Ghibli's headline achievement would likely be considered to be Spirited Away (although I prefer Princess Mononoke), which is nearly as old, but they've still put out some solid work since then.

As dragontamer pointed out, Gainax has also produced Gurren Lagann in 2007, which is definitely a pretty big hit, even if it wasn't the phenomenal success of Evangelion.

I mean that anime is Evagelion, it is like using Star Wars to showcase Lucasfilm, there is most accurate representation of the studio's accomplishment, as well as assets (used to be).