Quoting: Nezchan

Quoting: vertigop.s: HL1 first -> HL1 expansions if you really dug the original -> HL2 -> Episodes -> Alyx -> Black Mesa

How do OpFor and Blue Sphere work into this?

Those are the HL1 expansions I mentioned.

Quoting: chickenb00

Black Mesa is for fans who have already experienced the games for what they are.

Yes and no. I agree Black Mesa is definitely for fans of the series and IMO the superior way to play the OG campaign. I'd argue if someone had a mild interest in playing HL1 (they want to experience the story because they've always heard so much about it or they're new to gaming), advise they play Black Mesa. If they're the type of gamer who enjoys or tolerates older games, play HL1.

I politely disagree - I think HL1 is still eminently playable in 2025 and should be attempted first. If a player bounces off the game due to the graphics then by all means play Black Mesa.

I don't think it's accurate to say that Black Mesa and HL1 have the same campaign. They are radically different in most every way. HL1's largest lasting impact is not the story itself but how it's told and I think experiencing that is what's important - not the story beats.

I'm not saying don't play Black Mesa - just don't confuse it with being some sort of remaster of HL1. It's a full re-imagining, not a remaster or remake.