Ef is mediocre romance with overblown drama & personalities and with desperate attempts at stylish art direction that comes off as sophomoric and reeks of trying too hard.
Zetsubou Sensei is utter fucking shit. Only the first episode was anything remotely good. The rest is masturbatory bullshit trying to pass itself as ironic when it fact its just another panty shot anime despite what it thinks it is, or wants the viewers to think. Also tries too fucking hard.