If you’re a fit man, the black/white/grey v-neck cotton stretch t-shirt by Calvin Klein has been the best t-shirt for years. A lot of Amazon-ish companies have been marketing the best fitting t-shirt for men but Calvin Klein’s been making it for a decade.
Get the non-stretch cotton if you’ve got some fluff on you. And they run kinda large. If you wear a large normally you might wear a medium in CK.