What cable companies make the best cables and sell them directly?

I was lucky enough to try 100+ different cables. Nothing get close to High Fidelity cables. The price bites, but these are the best of the best of the best. Rick is the owner. You can deal directly.

If grade his tonearm Helix Ultimate Reference as 10, the next in line would be Graham IC-70 with score 5 and next Hovland Music Groove 2 with score 4.

I got his power cables and RCA interconnects that are awesome addition to my line up too. Didn't have room behind my rack and money to try speaker cables.

i love my CARDAS CABLES. 

If you use the balanced XLR connections, you can use just well built standard Mogami or similar and not worry about it.  By design balanced XLR removes any noise or coloration within the interconnect.  

My experience. I can afford about $50 on RCA cables.

Audioqest Evergreen had a bad connection after the first removal. The Worlds best cable had no issues.

Speaker cable =install gear 10ga oxygen free copper. My friends joke and call me "ears" I notice nuances in music, love music, accuracy in instrumental reproduction. a Sax, bass, trumpet cymbal, voices, sound right. These are cheapo alternatives for people like me that have little cash, but like quality and excellent sound. This works for me. It is always fun to hear other people’s experiences.

I will add one more thing to the conversation. Your age and your hearing may impact how much difference cables make. I don't disbelieve people that say they notice major differences between cables however at my age and with my hearing rolling off around 12,000 Hertz those things they notice may not be apparent to me. So besides all the other decision factors that have been mentioned I would suggest taking that into consideration.