I'm talking about anime (or manga I guess) that might otherwise fly under our radar because from the first episode or from the advertising blurb the serious would seem weak.
Elfen Lied and Naruto wouldn't fit in here because they're rather famous and acclaimed (and Elfen Lied comes out of the gate at full throttle instead of slowly building up).
My example would be School Days. The blurb and first episode or two make it seem like just another kinda slow moving romantic type anime. However after a while it changes direction and is not only good but rather unique as far as I know.
Also it seems to be one of the few anime with an associated meme.
Yeah it's OK if you don't get it before watching and then maybe doing a little googling. Not that funny at any rate, but fun for occasionally sliding in Nice Boat comments to refer to something.