Speaker wire brands and strands don't make such a difference as using the proper gauge of cable. For a while, the in thing was to use stripped cat 5 cable for high end home speakers. 16 would be safe up to the crossovers, 14 would be better, 12 would be too thick to run and unneccessary. 14 is harder to find like Brett mentioned.
More strands make it softer and easier to turn corners. Most cables nowadays are so finely stranded that I don't think you have to worry about it. More strands = more resistance so having too much is actually bad. The big difference you will find between manufacturers is in the quality of the jacket. Cheap cables tend to have weak jackets or they will be really hard like cheap plastic.
If you follow Brett's advice and just stick with names like Monster Cable, Tsunami (by metra), Stinger, Phoenix Gold, etc, you will be fine. If you can hear the difference between any one of these speaker cables in the same gauge then you are superhuman. My favorite kind of speaker cable is the twisted stuff inside of a jacket because it's round and just seems to make the installation neater.
