I'll give the edge to SA2. As blown away as I was by SA1 at the time, the Amy and Big the Cat missions slowed the game to a grinding halt for me. I'm glad they cut that out in SA2. More killer, less filler.
Loved the soundtracks though. Wild Canyon, Aquatic Mines and Death Chamber are all stuck in my memory.
On that note, I prefer the DC originals to the GC rereleases. The GC versions just feel off.