I put them in 2 categories - those that can be manipulated without
human intervention and those that do not require that.

Requires human intervention:

1:  feather attached to string attached to stick.
2:  laser pointer

Requires no intervention:

1: live crickets
2: bottle caps - for some reason, my cat loves these things.  Most of
them are metallic beer caps, but plastic water-bottle caps seem to be
almost as good - the best thing is they are free.

There was a cricket death in my home tonite - it didn't last long, but
I could tell she really enjoyed it while it lasted.  Coincidentally, I
also noticed the crickets in the pet store tonite - they're not meant
as cat toys, but they're cheap and I think I may buy a few next time
I'm there.

The wobble-ball thing is also okay, although it gets annoying because
it requires batteries and tends to start banging itself against walls.

Any other good toys anyone reccomends?