No "fill all motives" cheat exists in the console versions (PS2, Wii, GC, PSP). The PC version has boolprop testingcheatsenabled true → Shift-click Sim → "Spawn → Sim Modder" or "Make All Happy", but this was removed from ports.
boolprop aging off (enter via cheat menu: L1+L2+R1+R2 / Wiimote combo) – Stops motive decay entirely.Use motherlode (50k §) for money to buy best objects.