My unending bouncing around may seem like it's yielded 100 played households, but since I tend to play a given story to a natural conclusion, it does take time to see that conclusion out (whether it's raising a kid, maxing a career, moving a sim from a low-end house or apartment to a higher-end housing situtation, or whatever), which places a natural brake on the total number of unique households I've played in my current (since I bought this computer last February) save. At last count it was 15.
Unless you count the ones I kill off. Those are over in five or ten minutes of real-world time, max. But my hall-of-shame graveyard's got over two dozen bodies buried in it.