That's not too easy and depends on how close you wanna get to the classics you named. After all, the PPG Wave, the Prophet VS, and the DX 7 all sound different.
The Prophet 12 should probably taken for what it is and not what it can emulate. It's currently the most flexible hybrid synth on the market that may be able to capture some of the characteristics of the instruments named above, but I think you'll only truly enjoy it if you aim for sounds beyond that scheme.
Sound-wise, I think nothing comes closer to PPG-esque sounds than the Modal Electronics 002 at the moment. It also has an overall instant big and luxurious sound.
And then, there will be the Waldorf Quantum soon, which will offer a whole different palette of digital options, among which there's also going to be granular synthesis.