Most evil Video Game villians

[Mr Bean]

Indeed. IIRC the geas which Yoshimo got was intended to be either mirrored with Imoen or straight up replaced (given that in the code there are some unused dialogue scripts for Yoshimo the latter seems to be true).

But since I absolutely adore Imoen, having her live is fine with me. I just wish they had not gone into the "hey, she is a bhaalspawn too" route with her, as that kinda devaluates BG1. Yeah, right, a second Bhaalspawn right under Gorion's and the watcher's nose...righto. It just does not mesh well with BG1 especially as she does not get dark visions or anything.

Had it been hinted at in any part of BG1 I'd be just fine with it.

Speaking of D&D villains

I cannot be caged! I cannot be controlled! Understand this as you die, ever pathetic, ever fools!

To think I was feeling good about Spellhold idea until that happened.

Except for Planescape all video D&D villains have been pathetic since then.

Neverwinter Nights? Evil snake lady/god who went down easy once I fetched the right shiny rocks
NWN:Shadows:A Medusa fine but generic as all hell
NWN:Underdark:Generic Evil Demon #571 even the twist was rather lame
Neverwinternights 2:King of Shadows is a generic villian, an undead being undead and evil. They had a shot with Black Garius but considering I foiled 90% of his plans it was easy to pull off.
Neverwinternights 2 MoB:Akachi who is lame another re-tread of the King of Shadows faceless evil thing that is evil.

[Thanas]

Indeed. IIRC the geas which Yoshimo got was intended to be either mirrored with Imoen or straight up replaced (given that in the code there are some unused dialogue scripts for Yoshimo the latter seems to be true).

But since I absolutely adore Imoen, having her live is fine with me. I just wish they had not gone into the "hey, she is a bhaalspawn too" route with her, as that kinda devaluates BG1. Yeah, right, a second Bhaalspawn right under Gorion's and the watcher's nose...righto. It just does not mesh well with BG1 especially as she does not get dark visions or anything.

Had it been hinted at in any part of BG1 I'd be just fine with it.

Agreed.

Speaking of D&D villains

I cannot be caged! I cannot be controlled! Understand this as you die, ever pathetic, ever fools!

To think I was feeling good about Spellhold idea until that happened.

Spellhold idea?

Except for Planescape all video D&D villains have been pathetic since then.

They all had less quality voice-acting. The voice of Irenicus gets me every time.

[Norade]

The battle at the end of Underdark is actually against an Arch-Devil, Mephistopheles lord of the 8th.

[Mr Bean]

Spellhold idea?

Hey Gang lets sneak into the prison Irenicus and Imoen are both in, but it's okay since he's locked up and we can break her out easy enough. Oh shit he's broken free and controls the whole island! Well this is going to suck

They all had less quality voice-acting. The voice of Irenicus gets me every time.

The problem is motivation. None of them have been as un-nerving as Irenicus. Plus we don't get to know the rest of them as well as we do Irenicus. He's the big bad but he's in your face from Day 1 minute one.

The battle at the end of Underdark is actually against an Arch-Devil, Mephistopheles lord of the 8th.

Really? Well that is impressive except big M left exactly zero impact on me perhaps if he had been free the entire time or you had gotten that thing directly from him it would have been a bigger deal
Spoiler

If the Artifact you got between Shadow and Hordes had been given directly by him or him disguised as something else and his big reveal was he had been nurturing you along this entire time just so there would come a point when the Drow bitch would order him to kill you so he got a free of the deal he had made with her it would have been a great twist. He's this demon prince who engineer an invasion of the surface world by the Drow so he could be set free on a Prime Material world if once or twice his minions added you against the Drow to make sure that the day would come where you would make it to the Queen bitch and that she would arrogantly order him to kill you this freeing himself then it could have been a great twist but instead its a WTF out of left field ass pull

[RogueIce]

Me, in Fable: The Lost Chapters.

More seriously:

Officer Tenpenny from GTA: San Andreas. That guy was a huge prick.

Catalina in GTA3. It felt so very, very good to finally kill her.

[Keevan_Colton]

I do think that a lot of what really makes Irenicus is the excellent voice acting from David Warner, he just makes the character come alive.

[Brother-Captain Gaius]

NWN:Underdark:Generic Evil Demon #571 even the twist was rather lame

Generic Evil Demon?!

Mephistopheles, Lord of Cania, Eighth Hell of Baator is not a Generic Evil Demon!

Edit: Oops, someone already pointed that out. Sorry.

[Thanas]

The problem is that he did jackall. Heck, Demigorgon from BG2 was more of a threat.

[Brother-Captain Gaius]

Part of me wants to agree -- Mephistopheles was more or less a non-issue for 2 of the game's 3 chapters, especially if one isn't familiar with Planescape cosmology and who's-who. So in that sense it's a sort of "wtf? where did this come from?" in the final act.

On the other hand, I think the presentation is actually pretty good, especially for an epic-level campaign. Meph is a sort of "hidden evil" behind the red herring supposed-villain. Everything seemed to be coming to a head with Valsharess, and then when shit hits the fan at what one thinks is the end and you get to sent to Baator, it got a bit of an "OH SHI-" out of me. Plus talking to random NPCs with "Why so glum, chum?" and getting "Why so perky, berky?" back is pretty ace.

[Darth Quorthon]

I found Admiral Tolwyn from Wing Commander IV to be particularly vile.

[dworkin]

Me, any incarnation from the Civilization series.

From mortaring the stones of the Pyramids with the 'blood of a thousand slaves', razing entire cities because 'they were in the wrong place', conscripting millions to provide enforcers for my police state, gradiose vanity projects the reason for which is a distant myth by the time they're completed, invading my peaceful neighbour because a) I'm bored or b) I want to try out these new weapons to letting the entire world go to pot so long as the spaceship (which I'll be leaving in btw) gets built.

And then it's off to Alpha Centuri to continue said atrocities except I'll nerve-staple your ass for the first offence and throw you to the mind worms for the second.

[Darth Yan]

wow. I'm pretty much the opposite of you in civilization iv

[Chaotic Neutral]

New Vegas: Caesar - Why have slavery, no technology, and subjugation of women? FOR TEH EVULS!

40k: Khorne - BLOOD FOR THE BLOOD GOD!

[Darth Fanboy]

My Fable characters are normally quite vile, as are my civilizations in any of the Civ games. (Especially the ones in Test of Time that completely relocate to other levels of the map and then indiscriminately nuke in order to collapse the environment of the other maps on a worldwide scale decimating the population and resource production of other civs.

But the OP did specify Video Game villains that I wanted to take down and take down hard, so why not:

-Lucien Fairfax, Fable II

Killed my character's wife and child, but the motherfucker also shot my dog. I spent a lot of time training that dog to tear out throats, play fetch, to piss on the feet of my detractors, and find buried treasure.

-Luca Goers, Final Fantasy X

Not the main villain or even a vital part of the game but every time I pull off that particular blitzball upset it feels pretty damn good.

-Pokey, Earthbound

What a dick.