Today I decided to play thru good ol Vanilla HL1 again and I came up with an idea: We all share what moment defined Half-Life for you.
For Me it was During Surface Tension and it was when you were crawling through a small pipe and then at the end a Soldier threw a Satchel into the pipe. He then set it off and you had to Outrun the Fireball. That was the defining moment of the Half-Life series for me. Share what defined the series for you in the comments.