This isn't a question of who would most likely buy PS as a going concern, but who would treat the brand right and take it from strength to strength. So ignoring the current financial capacity of any company to buy the brand, who would be the best to do right by the brand?
Personally I think Sega. For one thing I think core Playstation fans would be cool with Sega taking over because Sega is about gaming and they have a decent reputation, and in the gaming context they are not Nintendo or MS. Sega would really understand the essence of what makes the PS brand what it is in gaming, and they would inherently know what needs to be done to keep it at the top. Sega's own IP added to Sony's first party line-up would make a formidable force against MS and Nintendo. But not so formidable that third party studios would see them as a threat. And Sega would work with all 3rd parties.
Sega would see PS as an end in itself. Every other company would see it as a means to an end. I would not trust Apple, Samsung or Google to treat the PS brand right. Nintendo and MS would kill the brand and just buy it to absorb the first party studios.
“The fundamental cause of the trouble is that in the modern world the stupid are cocksure while the intelligent are full of doubt.” - Bertrand Russell
"When the power of love overcomes the love of power, the world will know peace."
Jimi Hendrix
