I remember in HL1 when you just finish the cliffs section of the game. You're a bit fatigued and low on health after the helicopter fight, then you reach the drain pipe and think you're safe....and suddenly a headcrab jumps out at you.
Startled me so much the first time through that I actually...
I say it's the same rocket launcher the G-Man took from Gordon at the end of HL1. (Government property, remember?) He then, knowing Gordon was on his way, gave it to Cubbage, knowing that Cubbage would then give it back to Gordon.
The companion cube was my favorite, if we're including Portal
However, in the main HL series, I liked the two men you meet on the train at the very beginning of HL2.
Guy on the train: "I didn't see you get on."
Breencast: "Let me read you a letter I recieved today.
Dear Dr. Breen,
Why has the combine seen fit to suppress our reproductive cycle? When will they deactivate the suppression field and let us breed again? What gives authority over mankind...
I've got a 2.0 GH Athlon processsor and a GeForce 6600 256MB PCI-E vid card. I get around 15 frames per second outside, but in towns or dungeons, I get a steady 30FPS at all times :)