Zombie Vortigaunts. I think that would be epic.
Or maybe just a better A.I. to the npcs, that would be good too.
Zombie stalkers would work simply because the laser is their only offensive option. They have no hands.
except that wouldn’t work.
But how could they fire the laser? It would kill the headcrab… right?
exactly
Maybe the headcrab would be on sideways 
Already thought that up, i only got one comment :[
(Tornronim) I wouldn’t mind seeing bullsquids again, but who says they’d survive long enough to adapt to an arctic environment.
Don’t bring it up again
As much as I would like to see some of the old enimies come back, I think that they should just stay gone. unless you get to go back to Xen in episode 3. I do think however that the advisors should be killable enimies at some point. As for weapons, I think you should be able to find some Aperture prototype weapon on the Borealis that you can use against the advisors.
I almost don’t want to fight Advisors, I prefer them as the all powerful and fear inducing Combine.
I think you go to Xen in Half-Life 3:
you just quoted a post where you were speculating episode three. :s
besides, what would gman gain from doing that.
Sorry meant to say ‘wouldn’t’
He lost control of Gordon in Episode 1. This way he would have a better idea about where he had him.
But you’re right, it’s a stupid idea. :zip:
ON TOPIC: My suggestions so far is Zombie Vortigaunts and Fighting Androids. I got nothing for now. Both idea-wise and constructive-critisism-wise. 
Zombie Penguins.Nah,joking.
How about…Barney dies in Episode 3 transformed into a Advisor ?! … (Waits for swearing parade.)
G-man is actually a secret molester . Joking…again .G-man is a certified interstellar lawyer who is contracted to save Earth from a dying crisis.Period.
No,no ,wait ,I got a better one.Gordon is not human. You didn’t expect that did you?.
…
The combines saved the earth from Global Warming!
Yeah,they saved the earth from Global Warming and instead initialised a Global SWARMING. That’s really great.