I play electric so I should not complain when someone steals my END, but fighting Freakshow is just annoying. I am not sure who among them is stealing my END but it is happening.
Whereas Arachnos is interesting to me because you have mu stealing END and blood widows blinding you - but I can tell who they are and prioritize them. It is not something that just happens to me, it is a tactical part of the fight.
On the other hand, low level villains I just hold the lieutenant and then beat up the minions. Other than the outcasts, the villains do not seem to have any tactical differences between them worth noting.
My favorite enemies to fight are probably Banished Pantheon. The shamans make for interesting fights and the totems just look so cool.