I'm playing HL2 again after 7 or 8 years, the first time I saw HL2 was a guy playing the demo and I was blown away by how the physics worked. Ten years later and the experience still holds up, the controls are pretty good even the driving sections (I must be one the few who enjoy these sections) and the atmosphere works to make me feel immersed in the game. Some design choices nowadays could be seem as atypical nowadays like no health regen and no full body awareness (I like to think Gordon Freeman as a telepathic physicist).
I just started replaying Black Mesa, with a crapton of mods installed (Surface Tension Uncut, On A Rail Uncut, Loop Mod, Vent Mod, a mod that restores the original marines voices, and a change to the skill.cfg file to slightly dumb down the marines and make them more reasonable to fight against), with the intention to play HL2 right after I'm done with BM. Great minds think alike and all that.
Oh yeah, for the past week I've been receiving on a daily basis invites from guys who have like 5 games tops and have their profile set to private. Nothing shady about that, nothing shady at all.