To be honest, I love Half Life 1 and 2 as excellent first person shooters. But anyone praising the games for their story telling are either blind or playing a very different game to me.
Both games have barebones, completely minimal storyline going for them. There's a difference between telling a story in a very subtle manner, and not telling any story at all, and HL falls into the latter.
I could ask a million questions for both games, What is this, Why that? And I guarantee you that playing through the games with the sharpest eyes possible would not answer any of them.
Half life = Excellent shooter - Rubbish story which frankly is almost non-existant.