I don't know if anybody has told you this or not, but i think you should buy it because it's dirt cheap. Naw, nobody would have thought of that.
I'll tell you, my clan has three members, including me. The other two both went out and downloaded Counter-Strike via Steam for "free". Then they tought it'd be cool to just get a cd-key generator and MAKE there own keys... illegally. So, needless to say, I'm once again the only member of the clan because the other two can't connect with their fake cd-keys anymore.
So, you see? The only way to get half-life is to buy it. If you download it for free, then it's warez (pretty illegal stuff) and then ur a lame-ass. If u wanna do that stuff then I got a map de-compiler... ooh! and a couple of nice wall-hacks and aimbots.