As with everything. your preference will differ.
However, I strongly recommend NOT getting Tomato pack....horrid and I have not met anyone who likes it.
My favourites are the chilli, chocolate (for making a hot chocolate at night) porridge (some say it's too sweet), Thai chilli, nut fudge bar, peanut bar. But I still have all the rest for variety.
I suggest you try and see what works for you.
Still not tried any water flavouring yet. so can not comment.