RE: What order should I play the Half-life series in?
The above question was closed as 'primarily opinion-based'. I believe OP was asking about how the different Half-Life games fit into the overall Half-Life storyline, to better understand it (an answer could include explaining how the games are ordered chronologically, and/or which games are important or not, to understanding the main story). I don't think that's primarily opinion-based at all. If it is, it isn't "bad subjective". I think that it's akin to this question: What games and order should I play the Metal Gear series games to better understand the story?
Should it be reopened or should it remain closed?