Ever since this thread came out, I have made a deliberate attempt to try different root beers ! Here are the results of my taste tests to date:
1) Boylans Birch Beer
2) Hanks Root Beer
3) IBC Root Beer
4) Boylans Root Beer
5) Virgils Root Beer
6) A&W Root Beer
7) Thomas Kemper Root Beer

I still have several more brands to try !!!