I’ve been working with a guy on this Minecraft map, and it’s finally finished: http://www.minecraftforum.net/forums/mapping-and-modding/maps/1549373-black-mesa-in-minecraft-with-mobs
It features HL (except Xen chapters), Opposing Force, Blue Shift and Decay fully rebuilt in Minecraft. He was the builder and texture/sound pack artist, I was the main redstoner. I think that considering it’s built on Minecraft’s engine, it’s on par in terms of quality to our Black Mesa.
Give it a try!