Well, for me. As I am aware that everyone is different.
My criteria is:
non wired
stretchy band without back clasp (I am always very aware of the clasp when I wear one)
padded but not removable ones as they often don’t sit right and if you accidentally leave one in end up all scrunched up
Still give reasonable support and shape.
Anyway, it has been a long frustrating and often costly search but I finally found a bra I am happy with so I thought I would share it in case anyone else is fussy in the same way as me.
https://www.boody.co.uk/products/wireless-full-bust-t-shirt-bra-black
Only available in black, white and “shell” but hopefully they will do some more colours soon.