The original version shipped with the A1200. It's perfectly fine for most AGA games but lacks some of the modern filesystem support found in newer versions. Kickstart 3.1:
If you want to dive into advanced 3D titles like Gloom or utilize high-end Workbench resolutions, upgrading to a Motorola 68030, 68040, or modern PiStorm accelerator will dramatically increase your framerates. Conclusion amiga 1200 roms pack better