I played the PC version of Resident Evil 2 before any other version. It has a ton of bonus content not seen in other versions of the game (as I was very disappointed to discover when I bought it for the GameCube). Plus there are various fan-projects for things like higher-res video.
Dreamcast got those bonuses for the 2 and 3 ports (plus VMU support) but yeah then the Gamecube ports were just the PS1 versions.
Lucky Dreamcast players! I never had a Dreamcast back in the day, so never got to play those ports.
I saw a disc only copy of RE2 DC used a few years after the Dreamcast croaked, and like a goof I didn't pick it up.