I'm not young. But 25 years after the hype, I am finally getting around to playing half life (1)! Stupidly missed the free action, but paid a few eurocents for it. They're totally worth it! Awesome game, holds up very very well after two and a half decades!
I’ve only played Black Mesa, and did so just last year. I haven’t played the original but had a ton of fun with the remake. I gotta try the second one soon
They are different though (as far as I remember) and while I think Black Mesa did some major improvements, cut some dull parts and modernized a lot of it, but few memorable moments are gone.