Whichever version is easier for you to get/run, honestly. It's the same game.
Text: They're basically the same. A few dated references and character names were updated. I liked Mack better than Claymorton, but I get it. Croaka Cola is obviously an improvement.
Graphics: The remake is just better. The original was early 3D pre-rendered as pixelated sprites, which was never a great era in game art history.
Animation: The original is better, this is my biggest complaint with the remake. Some things are kind of weightless and floppy.
Music: They're both great, the remake maybe a bit better. It's entirely reasonable to prefer one over the other on a track by track basis.
Mechanics: The remake adds some extra systems to the combat. I don't think they really add anything. They don't ruin anything.
Content: The remake has a series of post-game boss fights with weird remixed mechanics. They're not incredible, but it's more stuff than the original had.