Essential cat toys?

[Yule Cat]

Hey there,

I'm busy writing an article about essential cat toys.

I already have the "rods" (cat dancer, go cat catcher, Nekoflies),
Braintraining/foodpuzzles.

I'm missing something, but I can't think further than the usual "balls".

Ideas?  

[M-EWTBAC Mule]

I think it depends on cats and probably is far from what your looking for sweatdrop but a few of mine can't seem to be satisfied unless they have their own larger sized "toy" stuffed animal or sock monkey or something, to bully around. Especially if they don't like play with other cats sometimes c: or can't