CD keygen's

Where do people go to get keygens. my friend just got Half life 2 and he said if I can find a CD key for it I can install it on my comp to, so where do you guys go i found a site called http://www.crackfound.com/ and they have a whole bunch of cd key stuff but I have no clue what to look for.

i use andr.net but make sure to use firefox with noscript, they used to be a "no bullshit" site but i guess they sold out to advertisers.