And while we’re at it, are the Beatles better than Wayne Shorter?
Seriously, though, I see the value of GOAT questions not so much as a ranking mechanism, which can get a bit too masturbatory for me, but rather as a way of learning from colleagues about great new resources.
With that in mind, I have to mention Igor Levit, the increasingly popular Russian pianist who, despite being too current to fit into a larger perspective, is certainly up there with the best of the best. And if you read his bio & interviews, you’ll discover that he’s an interesting fellow to boot, on a personal level.
Check out his performance on "Rhapsody on a Theme of Paganini" with the Wiener Philharmoniker (available as a Sony Blu-ray import, a PBS special, and a streaming video on Tidal). The first time I heard it, I cried -- and I’m hardly the type to cry easily. Less impressed with his Wagner transcriptions, but surprisingly, I find his Bach to be as nuanced as his Rachmaninoff.
Igor may not be everybody’s "greatest", but IMHO is certainly worth seeking out.
My 2c.