In your opinion, which of the Diadochi tried to follow what Alexander would have wanted most closely after his death?
Hard to say, in part because nobody was powerful enough to impose what Alexander (probably) wanted. Krateros came closest in power, but even he decided it was smart to ally with Antipatros (and Antigonos). Nor was he (or Antipatros) as keen on the fusion of empires that Alexander wanted. But at least they seem to have wanted to hold things together, but wound up against Perdikkas.
Perdikkas--and Eumenes--were closer on the inclusion of Persia, but Perdikkas was both more arrogant and thought smaller (he wanted to be king/king-maker), and neither man was especially well-liked. Ptolemy was hell-bent on carving out Egypt as richest, and Seleukos kinda came out of nowhere to eliminate Perdikkas and then fight Ptolemy. Leonnatos was always a hothead and got himself killed even faster than Krateros. Like Ptolemy, Lysimachos decided to carve out his own spot, but up in Thrace.
I think that's the real problem. None of them was strong enough, or sold enough on ATG's vision. So I think my honest answer here is: None of them.
Alternatively, and only maybe: Eumenes, because he had the least status going into it--although that might just be Plutarch's framing of him. And he was too ornery to work with Antipatros or Antigonos, although he got on well with Krateros (supposedly).
