Vasilevskiy. Among those in the NHL right now, I think Gibson and Saros will also be close to the the top.
The best prospect outside the NHL is Samsonov. Shestyorkin is another with a good chance to be one of the best in the NHL. I don't know why so many are naming Sorokin. Sorokin has always been worse than Shestyorkin, yet so many name Sorokin, but few name Shestyorkin. The Russian NT goalie coach even said recently that Shestyorkin's game has developed well the last few years, while Sorokin's hasn't. I guess the initial season that Sorokin got KHL minutes while Shestyorkin got it a year later still carries over to today in perception. Thats not to say Sorokin is bad. He's a good goalie, but I'm not sure he's tracking towards being one of the best in the NHL.