You’re totally right, haha. I was just so excited while posting that, in my hasty attempt to include the later games’ communities, I just blanket-statemented the whole series! Thanks for catching that 😅
Morrowind! Besides the wealth of non-story quests, the modding community is HUGE and lets you add EVEN MORE CONTENT. (To be fair, the modding communities for all TES games are massive.)