Most "powerful" emperors of Rome

I am curious, who were the most prominent emperors of Rome? I am going
to try to divide this up... Some emperors may be used more than once,
of course.

Who was the most tyrannical emperor?
Who was the most merciful emperor?
Who was the the emperor with the largest military power at any point in
time?
Who was the funniest emperor?
Who was the craziest emperor?
Who was the laziest emperor?
Who was the sleepiest emperor?
Which dictator built the most infrastructure?
Which dictator valued education the most?
Which dictator had the most wives?
Which dictator did the best for Rome's general population?
Which dictator did the best for Rome's aristocratic culture?
Which dictator was most selfish?
Which dictator was most selfless?

Anything else fun you can add/answer?

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