There are various flavors. I think I like the guava kind best, but the raspberry and cranberry ones are also decent, and the strawberry one is acceptable. (The grape one seemed overly vinegary to me, and I've never tried the mango one as christychristy reported that it was vile.)
I was poking around online today to find a picture of the bottle to show some online friends, and I happened across this review, which I found very amusing. (Also, it contains a picture!) There is no doubt that this is pretty strong-tasting stuff and not to all tastes.
The ingredient list for the Raspberry Rush flavor is:
Ingredients:Update: I found the product's official website: http://www.gtskombucha.com/synergy.html
95% G.T.'s organic raw kombucha, raspberry juice, and 100% pure love!!!