I'm pretty sure the complete, definitive and best quality version would probably be the actual master tape, but it has certain drawbacks in terms of convenient playability and availability.
At any rate, I'd be very interested to hear this in lossless, not a YouTube-upload, and compare in detail. I can't say anything useful about it now, but it seems that these Bowie-box sets overall have been very well produced in terms of sound quality, at least that's what I've been hearing.
The Kurgan wrote:
It's the complete and definitive version, no brick wall.
Listen to it in lossless.
Isn't the complete, definitive and best quality version the original 12 inch single?
I have the original 12" vinyl single, but I wouldn't call it definitive, although it quite possibly is in terms of analogue releases.
I'll stick with what I consider to be the current and definitive domestic release, ie. the Bowie RE:CALL 3 CD.
It is also available on vinyl, although I'm not sure if any digital processing was used during the remastering.