Tough one. U.S Games do all they can, I fear, not to have the perfect, well done "as-it-was-intended" RWS. So we have to have half a dozen mostly OK ones but with one or more aspects not quite right. And on tenterhooks that one day they might just do it.
I love the lines of the drawings on the PCS Commemorative set deck. So sharp and clear. But not the backs and the fake ageing. The cardstock of a Pam A, B or C &c doesn't age like that. It's purely cosmetic.
I love the backs of the Original RWS. But not the very blotched High Priestess, King of Pentacles and a few other cards
I love the Colouring - and box - of the Rider & Co "Blue Box" edition. But not the backs.
I love the lack of lamination in the Rider & Co Blue Box and also the older early versions. And also the lack of a brazen "copyright" symbol branded on the front of the card
Overall, I would say my favourite is either an old Rider & Co from the 60s/70s (no copyright, and I overlook the backs) for sentimental value. Or a first edition Original RWS from 1993 (?) which has the nice Belgian cardstock. That's the one I tend to use more, but I like both of these two they're so well used too.
Of course I love my Pam B but that's a case apart. I'm sure my favourite version if I could have one would be the Lily & Rose backed Pamela A because I prefer that back to the crackle backed version.