carnival73: I thought the trailer for the first Portal was awesome - especially at the end of it were the female robot voice states snidely "This next test is impossible."

I have but still haven't played the first one. I was tickled pink to see that GLaDOS carried over into the second.

And I'm not sure if they put a spoiler trailer showing the end of Portal 2 but that "Eye" robot with the English accent had me laughing out loud.

OmegaX: I'm pretty sure they already changed the actor that recorded the voice of the robot with the english accent because the one in the original trailer was just a Valve employee that they used as placeholder. Many people preferred him over the new professional actor, though.

I've liked the trailers that showcase the new Aperture Science test objects like the slippery gel.