Named Game of the Year by over 50 publications, Valve's debut title blends action and adventure with award-winning technology to create a frighteningly realistic world where players must think to survive. Also includes an exciting multiplayer mode that allows you to play against friends and enemies ...
Black Mesa is missing nothing from the original, polished every single aspect of the game to a beautiful shine and it's relatively cheap. You aren't missing anything, it should be considered the definitive way to play the original now IMO.
Apparently elsewhere in the thread people are saying the AI may not be as good.
I remember seeing Half-Life on my friend’s older brother’s computer as a kid, and I never played it. I did play 2, and by the time I considered playing 1, I grabbed Black Mesa because it just looked so much nicer. I enjoyed it for sure. But I also played it before they finished so maybe I should go back and play it again.
I've only ever played HL2 on Orange Box on xbox, but I'm definitely thinking I might have to try the original because I remember HL2 being a good time, for the most part.