Caturday: What is your cat's favorite toy?

[foxfirefey]

So, recently I got my cat a Neko Fly rod with the mouse end, and my cat is loving it. He's much more engaged with it than he was with the one that was just a ribbon of polar fleece. I also got him a big stuffed salmon with catnip inside, which he attacked and slept with for a couple of days, but then seemed to lose interest in it. I'm wondering if he'd like it again if I ripped open the seams, put more catnip inside, and closed it back up.

What is your cat's current or past favorite toy?