I shoulda checked in, for sure.
For me, heinousness is a matter of style as much as scale. And for my money a lot of the big world / galaxy-smashers on the list hail from rather too moustache-twirling places on the Villain Spectrum to really make the grade (cf. House of Duras). Never much cared for the way the Borg Queen concept turned the Borg (at least poetically) into a kind of insect hive analogy, either, though Alice Krige is awesome.