I am a self proclaimed root beer connoisseur, due to my informed and discriminating taste for the brewed root. I have been scouring the world over in search of the finest of root beers and have compiled a list for the top shelf. The list currently stands as follows (not listed in any particular order):
Red Rock: The Red Rock Brewery Company brews an excellent root beer in house. It is spicy and robust, drawing from a strong tang of cinnamon and anise. I like a root beer that has a bite, and this one fits the bill. Probably the best root beer I have ever had, certainly the stoutest.
Virgil's: I don't care much for the regular Virgil's which tastes too much like molasses just tossed in a glass of soda water and swirled around with a licorice stick. I do however fancy Virgil's Special Edition Bavarian Nutmeg, which has a dark smooth flavor, with a pleasant nutmeg taste and aroma. Unlike its sister beverage the SEBN doesn't beat you over the head with an overpowering licorice flavor. The licorice is there, but it has been toned down to contribute to the taste symphony.
It is one of the most expensive root beers available for purchase, probably because you end up paying for an old-timey bottle and stopper. It is available along the Wasatch front in Good Earth stores. While you are there you should grab a keg (yes it comes in a keg) of Virgil's Cream Soda, which is excellent.
IBC: It comes in a 32oz bottle, need I say more? IBC makes a fine root beer with a nice subtle kick. They also make the only palatable diet root beer, which tastes similar to the regular although it is a bit watery and a little too sweet it works in a pinch though, for when you feel like cutting back the sugar/cal intake, that is if you can push past the bitter aftertaste.
Bulldog: This root beer is second only to Red Rock's, and widely more available. It has a gentle honey and vanilla flavor that is sweet too the last drop and lingers for just a bit after.
Others to note: