well for me its a bit difficult because of I would need to know an encounter. For example, for leveling, I would go for more attack power. Should I reach a certain level of attack power, I would begin with crit (or agility) for certain slots. And for tanking set, I would go for more stamina.
That is a relatively generic answer, because nowadays for tanking stamina/str/agility have taken a backseat to armor/defense/dodge/parry/block/block value etc. With the upcoming bc changes, I will start adding in resilience, so I don't get hit as hard from mages/rogues/hunters etc.
Hope that was helpful