For an all day vape I really like sour citrus flavors (peach, strawberry lemonade, pineapple, grape, things like that.) But I have to keep at least 2 on hand at all times. I chain vape and even when I'm drinking a lot of water in between puffs I will still go flavorblind if I don't change them occasionally. Its not a huge deal, it basically just means your juice tastes muted and you can taste the vg a lot more, but it can be tiresome and it doesn't go away until you change flavors anyway.
For curling up with a good book I have some clove flavored juice. Pairs really well with tea and puts me in a reflective mood.
Aside from mint flavors that's about all I really like.
I never cared for the pastry/dessert flavors that contained diacetyl so I don't keep up with their news, but I believe all diacetyl was phased out of juice 5 or 6 years ago. If you are still worried about it just avoid anything that sounds "buttery". The only reports I ever heard about juice containing vitamin e acetate weren't about this kind of juice at all. They were referring to cartridge vapes (for using thc, not nicotine) and shamelessly lumped our juice into it just to help cast fears and doubts on vaping.