Ah yes, the Half Life: FULL LIFE CONSEQUENCES! series. They only finished it recently, and it's based on a proper fanfiction.
Also, PLAY HALF LIFE! I mean the first one set a new standard for FPSs, so nowadays the average FPS is about as good as the original Half Life, but Half Life 2 and its episodes just go leaps and bounds ahead in terms of story. Actually, just buy the Orange Box, it's only £15 for the whole Half Life series, plus Portal and Team Fortress 2. (the best deal in gaming history!)
Actually... it doesnt have HL1 so you can buy that seperately for like £4