In order of preference.
IBC bottled
AW tap (if its a good barrel)
Barq's
AW
IBC has a nice bite, but its the smoothest of the bottled/canned rootbeers. I've tried a lot of root beers, and its the one I always come back to when I want a really good one.
Barq's is everyday fare, AW only if its on sale for less than barq's.
PS anyone whos in the Fargo ND Moorhead Minnesota area. Stop into the HiHo Tavern in Dilworth at lunch time.
Doesn't look like much on the outside, parking can be a problem. Best homemade burgers & fries you'll find.
And they have frosty mugs they'll fill with good draft root beer.
Ohhh and you can get it all & change back from a 5$.