SE (1st generation) — also my first Apple Watch 🙂
I might be compelled to upgrade next year or 2026, when the fourth generation SE will presumably be available.
My watch battery health is estimated at 81% and it easily lasts all day, anywhere from 20 to 50% remaining charge when I go to sleep. My cellular provider doesn’t support Apple Watch, so that capability is pointless. Features such as the larger display and double tap would be helpful, but I’m very willing to wait for those.