I tend to frequently play 1.7.10, 1.8, 1.12.2, and 1.16.5. But my favourite out of these is probably 1.7.10. The modding scene was really at its peak then, at least that's how I feel. And I continue to play modpacks to this day on that version, (lately GregTech: New Horizons. It has been a blast)