I've tried several varieties of Pur, which is one of few gums I can find that don't contain, artificial colors/flavors, sugar, or artificial sweeteners (but that preferably do contain xylitol). I settled on this one since it was reasonably priced given my criteria and had good reviews.
Most of the flavors I've tried taste good. All of their other flavors I've tried are some variety of mint--both traditional mints like spearmint and peppermint, but also combinations like pomegranate mint and chocolate mint, both of which sound a bit odd but also taste fine. However, I think cinnamon is my favorite. I do have to main issues with this gum, the reason for my one-star deduction on an otherwise good product. First, the pieces are small. You'll need about two to get enough to really chew on, so even though a bag contains about 60 pieces each, you definitely won't get 60 "chewing sessions" out of each--more like 30. Second, with most flavors, the flavor doesn't last very long before the gum just starts tasting like nothing or even becomes a bit unappealing--for most flavors, I'd give it at most 10-15 minutes, though in the best cases there is usually at least some redeeming residual mint aroma. For this flavor (cinnamon), it's seems to be on the upper end of that, and the residual flavor isn't that unappealing. This is something I'm willing to tolerate for gum that has pretty good ingredients (and perhaps the natural flavors and sweeteners inherently just can't last as long as others), but it's something you should be aware of in any case. I mostly like to use it to help clean my teeth after having a snack or while driving (or sometimes just while bored and vaguely hungry) or at other times where brushing my teeth would be impractical, and for that purpose this works well.
To summarize, Pur is great, but the pieces are small and the flavor doesn't last that long (a tradeoff you'll find with most "natural" gums, it seems), but these are tradeoffs I'm willing to make. Cinnamon is probably my favorite flavor they make since it lasts longer and tastes good, but none are particularly bad.