The first one is actually called GLaDOS - as in, Genetic Lifeform and Disc Operating System. It's mostly a pun on DOS and Gladys, though.
As for Zeno Clash, you mean Father-Mother? Nah, just kidding, it's Deirdra... Daerdra... Daedra... *Wikigoogle*... Deadra. Impossible to spell...

I have a shameful number. I'll try to keep my list short:
Fio Germi (Metal Slug 2 and onward--yes, I'm a guns-n-glasses man)
Annah (Planescape: Torment--with that accent, how could Fall from Grace compete?)
Para-Medic (Metal Gear Solid 3--the perfect girl to take to the movies)
Maggey Byrde (Ace Attorney series--again, guns-n-glasses)
Shinobu Jacobs (No More Heroes: Desperate Struggle version--the hair, the sword skills, the constant misuse of the word "moe" . . . swoon)
April Ryan (The Longest Journey--as weird as her model looked in the first game, she won me over)
Samus Aran (Metroid--specifically Metroid Prime, where she looked like a proper, battle-hardened warrior and didn't shed her armor for the player's gratification)
King (Art of Fighting/King of Fighters--just an all-around badass)
I'm tempted to cheat and say Faye Valentine just because a Cowboy Bebop game does exist (never played it, though). But I suppose it's unfair to expect any fictional woman to compete with Faye-Faye.
And although I'm reasonably heterosexual, if push came to shove, I would let Naked Snake (Metal Gear Solid 3) have his way with me. He's a man's man's man.

He is NOT that feminine!
Crushes:
Every female character in DOA series.
Mona from Max Payne.
Zelda from Ocarina of Time.
The goddesses in Shaiya.
Rayne from Bloodrayne (She can bite me any day of the week.)
The chicks you bang in the God of War series.
Done.

Thats why it's my WIFES pick.

Just to break with tradition.
Were I gay:
1. Kane - C&C Tiberian Universe
2. Jon Irenicus - Baldur's Gate 2
3. Agent Smith - The Matrix (IIRC, he shows up in one of the horrible adaptation games, so bleh.)
. . .Clearly, evil does it for me. Or being able to talk like a psychopath. . .
However, being not:
1. Amalexia - Morrowind (Something about the "I'm a demi-goddess and batshit insane" thing really does it for me. *Coughs*)
2. Tanya - RA2 (What redblooded RTS playing male hasn't at some point?)
3. Anna Grimsdottir - Splinter Cell (Odd choice? I think so.)
Other than that, I really can't think of anyone. And I had to stretch for those.

This.

Tali'Zorah vas Normandy. All the way.

I'm man enough to agree with you there. The second is mainly down to David Warner's excellent voice acting though.

Everyone is gay for Big Boss (the MGS3 version, that is).

Mitsuru from Persona 3

huh. I just realized I don't have any video game crushes. None, nada, nothing, never had. Weird. I scanned everyones list, fully expecting to see at least one character I had forgotten about that I thought was really awesome/sexy/whatever.

Really? �_�
http://img301.imageshack.us/i/4885makingof03wx5.jpg/
To be fair, she looks a tad hotter after being digitised =P

Sasha - TF2
<3
Also, after playing ME2 i've developed an attraction to various female characters
i luv ma femshep, Tali and Kelly
oh and EDI

Full win.