Uh...what part of the spoilered text has anything to do with whether someone's a villain or not? Depending on the viewpoint of the writer, can be a good thing or a bad thing.


What?

I was loosely paraphrasing the REAL awesome bad guy of Final Fantasy. You know who I mean.

As far as Byakuya goes, he is no villain. He was obeying the rules of Soul Society, and these rules weren't even so heartless (at least until started manipulating everyone for his own advantage). In DnD terms, I'd call Soul Society extremely Lawful Neutral.
EDIT: And so I would call Byakuya. He ain't evil. He just obeys the rules no matter how they are.

Sephiroth actually killed them, his sword being impaled through the president and aeris would say so, how he even used his sword to impale someone after advent children showed its truth length is debatable though.. Jenova may have controlled him somewhat, although after Nibelheim he was rather unstable he was a villan in that sense and did control his actions.

I understand your frustration over his popularization though. Kadaj's (From ff advent children) design was pretty good though for the type you describe, so I'm gonna add him even if sephiroth is the end result.

Byakuya was a bad guy in the context of that part of the story arch and not too much was done to redeem him in the eyes of Ichigo, whos till views him as a bad guy even if a lawful neutral bad guy. Which also screams dbz villan recycling, but no one seems to have mentioned them so i won't be the first..

I'm not sure if they were mentioned specifically, although I know the Witches of Eillean were mentioned, but Maya before and after the nix choker, Brann and Elfrida were interesting bad guys too.

I'm sorry, but anything related to Final Fantasy - those horrid games with repetitive, pointless gameplay and a plot that was cliche'd unto the jillionth generation - automatically sucks.

And since I recently re-discovered D&D, I'll name Halaster Blackcloak, possibly the most self-centred villain ever. He didn't want to dominate the world, he built his own and then proceeded to lure wave after wave of hapless adventurers into certain death!

Ysgraith. However it's spelt. That king bastard horror.

Trent, in "A spell for Chameleon" is one of my favorite antagonists.

And Bink, as one of my favorite protagonists.

Also Mithos/Ydraggsil in Tales of Symphonia makes for a good baddy.

I must agree that Byakuya was neither a villain nor particularly interesting. I'm also not a fan of Sepiroth, I prefer Seifer.

I'll add Grimmjaw while we're at Bleach, he's quite a neat villain.

What else... Verithrax automatically sucks, and that's it for now I guess.

And who exactly are you people listing here? The most interesting bad guys, the most evil bad guys, or all the bad guys you can remember?

The most interesting ones. I liked Ultimecia Ysrgraithe was just the incarnation of evil and cruelty, essentially. He went beyond just producing the emotions he needed to feed off to survive, he created sorrow lasting millenia, and when it started to fade, got ready to do MORE.

Oh, and Quinn because he didn't whine about circumstances. After he got possessed, he really kicked the arse of the guy posessing him with terrible, terrible whisperings - much like the mythological devil. Then sealed him into his mind and went on an arse kicking crusade throughout the galaxy, damning trillions of souls and ending up at the end of the universe, where his Lord won.
http://en.wikipedia.org/wiki/Quinn_Dexter#Quinn_Dexter

The second incarnation of Majora's Mask was pretty creepy. Wussy, but creepy.

Wow.. Majora's Incarnation and Majora's Wrath have got to be the most pathetic boss battles I've ever seen.

I dunno. Ever played KOTOR? Or KOTOR 2? They were like goddamn afterthoughts.

Mm.. maybe I'm just being swayed by the fact that i'm in the middle of MP3 right now, and so far the boss battles are simply amazing.

Luca Blight from Suikoden II

The true embodiment of evil.

Are you kidding? Luca Blight was a newblet. He petulant and over-the-top, yes, but a true embodiment of evil? Psh. Now Jowy was evil. Making me fight my best friend in an epic duel at the very end of the game? It brought tears to my eyes. Now that is evil.

He was deranged, but I wouldn't call him petulant by any stretch. Insane strength coupled with a complete lack of morals and tainted past. Jowy on the other hand was not evil, it was more that he did things that could have been thought as evil because of his own set of beliefs. But I still think Luca was a more prominent villain, because while you could understand the path he took if you read his back story, it still did not make him any less vile.

rakideshu from diablo 2
that little bugger used to kill my level 6's all the time on hardcore gawd i hate him.

Dakkon blackblade magic the gather omg uber card.

I love this book.

Blix, from Legend.

"Fire, fire, burning higher, making muuuusic like a choir!"

William, from Pillars of the Earth.