DH's Dr. and the Pharmacist both highly suggested he chill the water ahead of time, they said the colder the betterMy vote is Lemon-Lime, but they're all pretty awful from what I understand. Could you fill up the jug the night before and leave it in the fridge overnight, then add the flavor pack right before you drink it? I've heard it's a bit more tolerable if it's fairly cold, but you may want to double check with your pharmacist.
I know what you mean. I used the cherry years ago before my gastric bypass surgery, Dang near wrecked my tongue! I couldn't stand the taste of anything cherry for about three years afterward. lol
Something tells me that your best bet would be the flavor you like least anyway. lol
Good luck!
Kim