How American root beer tastes depends on the brand. Back in the mid-70s, I noticed that all the big brands started changing their recipe and stopped tasting like root beer, removing the sarsparilla root flavor. You can get actual sarsparilla root commercially and brew up your own root beer, but that's a lot of work. Since I find it best not to drink caffeine after 3PM, it's important to me to have a good root beer in the house to drink with popcorn or chips when I have a salt-snack craving.
Although I can drink a couple of the upper-end Big Brands, what I find works best is to go to a specialty or natural foods store and buy an assortment of "microbrew" root beers in individual bottles. It's pricy, but I don't need soda that often and you get what you pay for. I read the labels and get the ones with lots of spicy ingrediants. One of my favorites has a dash of mustard.
My husband is from Atlanta, so drinking Coke products is an act of patriotism for him out here. When the venue only offers Pepsi, he orders Dr Pepper, another product that got adulterated when the big brand bought it out. Original recipe Dr Pepper (as every Texas schoolchild knows) was invented in central Texas as a patent medicine and included prune juice in the recipe. I find there's little difference between it and Cherry Coke these days - both vile to my tastebuds but other people like them. That's what makes horse races.
On one visit to Atlanta we visted the World of Coke Museum (I'm not making this up!), where you can sample Coke products from around the world, view nostalgic commercials, and see Coke advertising collectibles. It's all very silly. But I realized on this visit just how insidious advertising is and how well they've learned to manipulate the artist's toolkit of emotional hooks when I felt myself tearing up at the "return to the hilltop" commercial.
For those of you who missed this advertising classic, back in the early 70s Coke took over the Up With People song "I'd Like to Teach the World to Sing," changed one line to say "I'd like to buy the world a Coke," and staged an elaborate faux-Up With People Happening involving people holding hands on a hilltop and singing the altered song. The "return to the hilltop" commercial involved a mother bringing her children to the hilltop and telling them "This is where it happened," with flashbacks and emotive music. I knew it was absurd and manipulative, but a combination of factors nevertheless produced the physical reaction of tears.
Be ever vigilant! I eliminate advertising from my life as much as possible (it isn't very, alas).