Gman seems ultra cool to me ever since that scene in episode 2. He seems more real, more friendly.
GLaDOS...Who couldn't love her, her humour, sarcasm, intelligence....*oggles*
Dog is teh lame. TBH hes one of the worse characters in the HL2 universe, all his walking animations are terrible and he slids around everywhere, he always freakin walks into me and the 'emotion' between him and Alex is non existant to me.. Also, the people calling him d0g.... *sigh*
And the WCC, although awesome, nowhere near as good as the turrets.
Myvote - Gman/GLaDOS