I dunno, when Half-life 1 came out it was breathtakingly detailed. the only game with better graphics was riven and that was a photographic game.
The AI was amazing and intimidating(we were coming from quake and doom here)
its the first shooter i remember actually having an in game story rather than cut-scenes explaining the next wave of shooting.
The lighting and sound were epic.
...and the intro just left my jaw hanging loose for its entire duration the first time I saw it.
it's easy to look back now and poo-poo Half-life 1, but it was truly groundbreaking and still one of my all time favorite games.
Halflife 3 would be awesome.
Sometimes I like to use words out of contents