Tukey HSD is generally a good option to control the FWER of all-pairwise comparisons, given the assumption of a conditional normal distribution is reasonable.
From what I read... What? Okay, yes it was Wikipedia... What? No, I don't usually read up on statistical tests on Wikipedia.... Huh? Well it sounded reasonable when I read it ...
Anyway, it sounds like Newman - Keuls is more liberal, in the sense that it is more likely to commit so-called type i errors over type ii errors. Your decision might rest on how you balance this trade-off .
[No Wikipedia articles were harmed in writing of this post.]