Pineapple, without a doubt! Especially with the ginger taste. I'm trying mango later today for the first time and might change my mind, though... Beetroot is an acquired taste, a mix of earthy, sweet, and sour. The first batch is always very thick, and it's good to dilute in (sparkling) water, with optional sugar for taste. Oh. I almost forgot about fermented oat, it's called kvass, also nice.