For favourites: Shulk (Xenoblade) vs Dagda (SMTIVa) - the guy that purged gods from his universe, VS the guy that wants rid of all religion from his universe (seriously, Dagda is just a mood sometimes). Shulk probably wins on variables, but wouldn't actually want to kill someone he sees a thematic/moral debate with (see Egil).
As for least favourites (and I'm going to get shit for this)... Kamina from Gurren Lagann is going in the supposed protag' slot
for reasons I itemized in my hour-long GL diatribe a few months ago. As for least favourite antagonist...? I have a few contenders, but none of them necessarily go in the slot. Let me talk through my thought process.
1) Lord Jirall (The Last Story). Between his hypocritical cowardice and being a corrupt aristocrat, I used to despise this prick with a passion. Looking at his behaviour in retrospect, however... not really. It's not hate I feel anymore, it's pity - and he's rather pathetic by today's standards.
2) Rossiu (Gurren Lagann). I know I already mentioned this in the video linked above, but what pile of cartridge on the town planning department thought it would be a good idea to "redeem" a dictator, and then overstay his term in office about 4 or 5 times over? Not to mention endangering an entire city he made a surveillance state, and scapegoated Simon, who despite not being too dissimilar to Kamina by this point (thank Raiko for that comparison) capitulates to Rossiu every step of the way?
Now the reason I'm hesitant to put Rossiu in the seat despite contesting the throne for my most hated character in all of fiction is the fact that the narrative juggles moral ambiguity for him, a 'road to hell paved with good intentions' kind of thing, hence his supposed "redemption". OK? Try calling him Adolf Hitler, see where that gets a society.
3) Saki Arima (Your Lie in April). Yes, the inciting incident of my favourite narrative punching bag in all of Anime is on this list (who here was surprised?). Has a similar 'attempt at redemption' thing as Rossiu (from beyond the grave, might I add), but as much as this psychological assassin makes me want to shit down her throat at the mere thought, I get the sneaking suspicion my hatred towards her would be infinitely
less if every party involved (Kaori, the public, and to a lesser extent Seto) weren't beaten 28 times with the idiot stick (Kaori wasted no time becoming the very thing she sought to destroy, Seto's turn to drag Kousei out of the room has no transition between being a decent mother and just being a bitch, and most of all, no one had the balls to just condemn Saki outright, amongst other things). Also we're talking in terms of 'who would win in a fight', so...
4) Endeavour (MHA). Outside of being the 3rd 'moral ambiguity' pick on this list, I don't think I need to explain this one. Being an abusive parent is always a fun thing to talk about (sarc), and the system facilitating his actions behind closed doors shouldn't require much for me to condemn it. But I think the main thing that leaves me torn is that Shoto is a character I
desperately want to like, but everything from the circumstances in Season 2 (like, dude, both your parents were bonkers), to it's state breaking down in Season 5 (something that is
seriously making me contemplate dropping the series) makes me wonder if this is a matter of the Son mishandling circumstances that he got right the first time (telling Endeavour to get ****** because that's who he associates fire side with), or it really is as simple as Endeavour being a shitty person. The arc hasn't yet reached Kousei tier, but it's getting dangerously close.
5) Alain (Pokemon XY Anime). Idiot by the end of Mega Evo IV becomes an even bigger idiot by the league, and faces no repercussions by the end of the gen. More at 6. (Moral ambiguity count: 4).
I'd (dis)honorable mention Ghetsis, but he's also a dead horse beaten. If only someone did a video on his respective alleg-
oh wait...
Y'know what, just for the sheer sake of argument, let's put all 6 in one fight. In winner order:
1) Alain
2) Endeavour
(top 2 is a toss-up)
3) Rossiu (technically scales to Simon, but philosophy makes him sit out)
4) Kamina
5) Jirall
6) Saki.
wait why is this post 10x longer than it needs to be?
EDIT: ****, I forgot Quinella (SAO) exists