Subject says most of it.
For me the best plot twists happened in two games.
Baldur's gate 1: When I found out that Seravok is actually Kovares spelled backwards, And that I spoke to him that whole time.
Baldur's gate 2: When I found out Imoen was a bhaalspawn aswell, I had no idea. :(

Worst plot twist:
Neverwinter nights 1: When Lady Aribeth turns evil, I mean, That was so expected, At the first episode when you find clues about that Cult, When you get the idea that the cult has a symbol of an eye, And then at the end of the first chapter, You see a cinematic with Lady Aribeth holding a sword that's on it's hilt was the symbol of the cult.

Feel free to post your own Best/Worst plot twists

It was all just a dream...
Nah, in seriousness? Assassin's creed was understandable and realistic enough, but it was so expected the master would go evil, and the ending was just too much of a big kick in the nuts to enjoy it.

Here is a message for the stoopid peoples, this thread will obviously contain spoilers.

Red Alert 3: When the premier betrays you, saw it from a mile away. Though you will see that coming a lot easier if you have played RA 2. For me, RA3 just had RA2's story with different names for characters.

Warhammer: Mark of Chaos: Another betrayal. When playing through the Chaos campaign Thorgar gets betrayed by the chaos sorcerer that helps you. The writing is so horrible that you can figure that out from the first chapter.

Good - FFT, FF6, MGS3, Vagrant Story, Parasite Eve

The ultimate plot twist: realising I can't get the three hours of my life back that I wasted on Dark Sector

"I'm sorry but the princess is in another castle" had to be said.

No More Heroes! Don't want spoilers but-the end is crazy!

Warcraft 3, when Arthas goes all teen angst on you.

OK, so it was pretty inevitable, but the cut-scene in which he kills his father remains one of the best I've ever seen.

In fact, all that games cut-scenes were brilliant.

The Jak series had some unpredicatble plot twists.

The best for me was Knights of the Old Republic (the revelation regarding your past). I didn't see it coming at all, and yet it didn't feel out of place.

The worst was Final Fantasy VIII, which was a terrible game anyway; the specific point that I'm referring to is when you find out that all of the characters knew each other as children, but then forgot. It seemed really, really contrived to me at the time, and since I was about 13, that means it was really fucking contrived.

Mother 3 had both a good and a bad plot twist.

Isaac Dodgson:
Bioshock has an awesome plot twist...one which I will not go into detail on, as i feel even putting it in spoiler tags would spoiler it somewhat

Yeah. I have to put my vote on that one too. I didn't see it coming, and when the whole thing is revealed I was pretty impressed. Hands down, I didn't see it coming, even after I walked through a room full of spoilers.

MGS2 is just one big plot twist in the Plant Chapter. I loved every second.

Not exactly the worst plot twist but the most expected (and most needed) was Ocelot's phone call to the CIA at the end of MGS3.

Since this entire thread will go with more MGS, I could figure out why Ocelot was The Boss's son.

I thought the twist in Star Ocean: Till the End of Time was really stupid.

songnar:

Worst plot twist ever - Definitely Assassin's Creed. I honestly felt betrayed by that ending.

It was a bit of a yes and no for me.

Good morning blues:
The best for me was Knights of the Old Republic (the revelation regarding your past). I didn't see it coming at all, and yet it didn't feel out of place.

The worst was Final Fantasy VIII, which was a terrible game anyway; the specific point that I'm referring to is when you find out that all of the characters knew each other as children, but then forgot. It seemed really, really contrived to me at the time, and since I was about 13, that means it was really fucking contrived.

FF8 has the two worst twists, because there's that and there's the whole retarded twist at the end that the real big bad is someone else you never even heard who's thrown in at the last minute.

Good morning blues:
The best for me was Knights of the Old Republic (the revelation regarding your past). I didn't see it coming at all, and yet it didn't feel out of place.

Yes.

Bioshock's twist was also pretty good. Certainly wouldn't have expected that if I hadn't heard about it before playing. But mentioning that game brings back memories of System Shock 2.

Also - obligatory mention of Aeris' death. Surprised that I'm the first to mention it.

CmdrGoob:

Good morning blues:
The best for me was Knights of the Old Republic (the revelation regarding your past). I didn't see it coming at all, and yet it didn't feel out of place.

The worst was Final Fantasy VIII, which was a terrible game anyway; the specific point that I'm referring to is when you find out that all of the characters knew each other as children, but then forgot. It seemed really, really contrived to me at the time, and since I was about 13, that means it was really fucking contrived.

FF8 has the two worst twists, because there's that and there's the whole retarded twist at the end that the real big bad is someone else you never even heard who's thrown in at the last minute.

Like in FF IX. God I hated that.

Planescape: Torment is like awesome twist city. Some of my favorites:

bad:
Star Wars: Force Unleashed. Who didn't see that one coming?
Reiko's ending in Mortal Kombat 4. He stands there, a portal opens, he walks into it, the portal coses, credits role.
did anyone think the ending to Perfect Dark was a bit of a letdown?

Good: Golden Sun, i really hope they do 3
Twilight Princess. she broke it, how could she?
Breath of Fire 2, play it, you'll see
Snowboard Kids, its not really an ending but its funny

how do you do those spoiler tag drop-downs?

Just write (spoiler="text you want to show")text you want to hide(/spoiler), but use square brackets instead of the round brackets.

best - Second Sight

worst - Bioshock

Heas:

Worst plot twist:
Neverwinter nights 1: When Lady Aribeth turns evil, I mean, That was so expected, At the first episode when you find clues about that Cult, When you get the idea that the cult has a symbol of an eye, And then at the end of the first chapter, You see a cinematic with Lady Aribeth holding a sword that's on it's hilt was the symbol of the cult.

It's far worse when her identical clone with a lightsabre, Bastila, does the same thing in KotOR, because you could see it coming a mile off (She even says in the trailer/intro "I'll never turn to the dark side", to which the audience inevitably must respond "oh yes you will", pantomime style, and because she gets captured in a stupid scripted sequence by jumping in to "save you" in a fight where you're scraping the decks with Darth Chinless' face.

FF8 has the two worst twists, because there's that and there's the whole retarded twist at the end that the real big bad is someone else you never even heard who's thrown in at the last minute.

The end of disc 2 of a four disc game is a funny definition of "last minute". Most people would consider that to be "half way".

Isaac Dodgson:
Bioshock has an awesome plot twist...one which I will not go into detail on, as i feel even putting it in spoiler tags would spoiler it somewhat

Definitely Bioshock but also Pokemon Mystery Dungeon... Yes yes i know its sad but it has to be said! That game had an epic plot twist.

Worst... Hmmm thats quite a difficult one... Probably FF8 - As loads of people have said, who didn't see that coming haha :)

Worst.

Not sure, but most recent is Mirror's Edge.

Another worst, Morrowind: Tribunal

And now a word *I mean worst* from Oblivion.

Oh, and FFXII. Don't even need to say it, do I?

Never really had a GOOD plot twist.

GloatingSwine:

Heas:

Worst plot twist:
Neverwinter nights 1: When Lady Aribeth turns evil, I mean, That was so expected, At the first episode when you find clues about that Cult, When you get the idea that the cult has a symbol of an eye, And then at the end of the first chapter, You see a cinematic with Lady Aribeth holding a sword that's on it's hilt was the symbol of the cult.

It's far worse when her identical clone with a lightsabre, Bastila, does the same thing in KotOR, because you could see it coming a mile off (She even says in the trailer/intro "I'll never turn to the dark side", to which the audience inevitably must respond "oh yes you will", pantomime style, and because she gets captured in a stupid scripted sequence by jumping in to "save you" in a fight where you're scraping the decks with Darth Chinless' face.

Thankfully that wasn't the big plot twist in that game. The bigger one was far better.

"No, Jon - You are the alien!"

In all seriousness, probably MGS2 would be my candidate for the worst.

The ending is so infamously convuluted that it makes it difficult to follow.

Best is either Bioshock or Kotor.

Gahars:
"No, Jon - You are the alien!"

In all seriousness, probably MGS2 would be my candidate for the worst.

The ending is so infamously convuluted that it makes it difficult to follow.

Best is either Bioshock or Kotor.

"And then Jon was an alien. Teh Edn?". Who saw that coming?
Anyway I personally think the Hitman: Blood Money twist at the end was very well done. I didn't see it coming anyway.

I loathe plot twists in general. Basically they all amount to the writer saying to the audience 'Ha ha I tricked you, you're stupid.' Which is even worse when you see it coming, in which case the writer is saying 'I underestimated your intelligence because I thought I was so much cleverer then I really am'.

Anyway the worst is Monkey Island 2. Way to ruin one of the greatest adventure game series ever chuckleheads.

When Fallout 3 forced you to kill yourself (or Lyons) despite giving you three radiation immune companions (Fawkes, Charon and the robot). Fawkes actually told me suicide was my destiny and he wouldn't interfere with it - despite that he could have prevented anyone from dying with no risk to himself.

What the fuck, Bethesda?