My fav bit was on the first play through of Half Life 1 and against Nihilanth I used the crowbar on his brain, I lost a lot of life in doing so but I survived and he died and its how Half Life should have been finished .... by bludgeoning an aliens brain with the symbol of power who Gordon Freeman is.
The sense of accomplishment was great.
I also loved the constant repetitive talk of it too, yeah, I spent 5 minutes of my life to ***** about the repetativeness of chatting about an epic game on a forum, was it futile?, yes it was, will it stop you making this or me replying to something I've replied to in life and on the net before? no. But while you have the right to make this thread, i also have the right to *****.
Just because I'm a bitter jaded forum user, yeah hate me, the elitist prick that I am.
Also the Stryder battles were epic.