Mods to make plants either vanish or (even better) switch to a different model when they're "harvested" instead of acting like static containers is a must. And I think most consider some kind of mod to at least chill out the cliff racers a little bit to be a must-have.
My usual mod set back in the day also included some light improvements to graphics (some of the later, heavier fixes involving wrapper-binaries and such didn't exist yet, or weren't stable), NPC schedules, and an Imperial Library just outside Vivec that would pay a little gold to be allowed to copy any books you provide that it doesn't already have (it starts empty) which would then spawn neatly organized on its shelves, mostly to give me a low-effort outlet for my book hoarding tendency in those games.