Cheap tweaks...What would YOU reccomend?

Justubes2, The Bybees are different than the others. Not sure what formula of crystals is being used but it goes beyond the other items you mentioned. My first impression on audio was not good. The sound was muted or just with no treble. Kind of like when I tried those RF clamps around my cables.
But, the sound did get better and better as the days went one.

11 of these is probably overkill, but that's the way I am. Besides, about half are used on my home theater equipment.

I'm getting ready to post another "next best tweak" item that costs about $9 each.

Use the felt side of the Bybees nearest the cables or equipment.

Justubes2, I also have great results with some of the WA Quantum Chips. The fuse ones, and the internal ones for transformers and capacitors, and some power cords work great, if you can keep them on. I have found no use for the speaker chips, and found those for pcs do nothing on HFC pcs.