Favorite cable brand.

+1 for Morrow.  I use MA5 for both speakers and interconnects and in my system, sounds perfect.  I prefer them over Cardas Golden Cross for speaker wire and MIT 3.3 shotguns.  They just have a detailed yet mellow sound to my ears.

If you choose only one brand, then Synergistic Researh. There are no other options for me. 

Nordost Odin !!!

I've had various favorites over the years, and have tried many higher end cables from lending library at Cable company. I'm done with spending huge money on cables. I now make my own power and IC's from various Helix DIY recipes. I use both VH Audio Airlock and  Duelund DCA in my recipes. One can make really amazing sounding cables here!

Power Cables
Stage III Concepts
High Fidelity

Interconnects & Speaker
Thales