I loved The Sims and The Sims 2. Bought all the expansions and most of the stuff packs. Got my family hooked on both! I've not yet picked up Sims 3 but my sister seems to enjoy it well enough when not playing WoW, NWN2, or Dragon Age.
There's a lot more to it than making them eat, clean, bathe, and use the restroom. It's the unexpected interactions, humorous situations, and the custom content that's truly appealing. It's fun to play god!