I tried Acon's multiplier.  I am not at all surprised that it won.
 
I also tried the Emissary amp sim, which I did not like.  The high gain sounded more like an out of control stompbox.  I thought the Flextron was a bit better.  It won't make me replace any of my amp sims, but I am sure I could make do with it if I had to.
 
I liked a couple of the effects in Guitar Gadgets.  I will probably keep it just for the Microcassette simulator.
 
What else did people like?
 
 

I like the lkjb ReFine plugin.  It's subtle, but has a pleasant effect on some mixes I've tried it on.  I think its ranking was hurt by a CPU-spiking bug, but that seems to be fixed now.  Here's a vid: https://www.youtube.com/watch?v=Sxp3x_W6ix8
 
lkjb famously released a free Maag EQ4 clone a while back.  Interesting developer.
 
Cheers,
Eddie