Half-Life: Source is pretty much the classic Half-Life ported to the Source engine. The graphics are pretty much the same, the main differences being water animations, the introduction of ragdolls, and some other physics stuff. And the skyboxes are more detailed now. The maps remain largely the same, so, if you like Half-Life, you'll like this as well.

Personally, I play both games whenever I feel like replaying the series, but that's just because I'm weird like that, as the story in both games is exactly the same, this being a port and all.

Half-Life: Source is pretty much the classic Half-Life ported to the Source engine. The graphics are pretty much the same, the main differences being water animations, the introduction of ragdolls, and some other physics stuff. And the skyboxes are more detailed now. The maps remain largely the same, so, if you like Half-Life, you'll like this as well. Personally, I play both games whenever I feel like replaying the series, but that's just because I'm weird like that, as the story in both games is exactly the same, this being a port and all.