I have voted for Constantine and Maxentius.
I appreciate the rulers who were very hands-on and made major changes to how the empire was run and functioned, thus my votes for Augustus and Diocletian in the previous polls. Constantine was very much of the same ilk.
As for Maxentius, he and his advisers were clearly very politically savvy, and I appreciate that. Maxentius (like Constantine) was the son of a Tetrarch who had not been allowed to succeed to the purple. Taking matters into his own hands, he used discontent in the city of Rome herself to seize power. The people of Rome and the senate were upset with the fact that the Tetrarchs had been mostly absent from the city, and they resented that Diocletian and Galerius had removed their tax privileges. Moreover, Diocletian and then Galerius were gradually disbanding and disbursing the praetorians, much to their chagrin. Maxentius used these discontented parties to take power in Rome, and he ended the persecution in Italy and Africa to gain Christian support as well. Maxentius' coins and building program then advertised him as the one true Roman emperor, the 'Preserver of His Own City' (Conservator Urbis Suae), in a world of Tetrarchs born on the empire's periphery and ruling from the provinces, especially using such claims after he lost the support of his father Maximian (whom he had brought out of retirement). Moreover, he survived two different military expeditions against himself and the city of Rome, the first by Severus II and the second by Galerius. The second by Galerius is especially impressive since Maxentius wasn't accompanied by his militarily-experienced father, and Galerius himself was the man who had avenged the Romans upon the Persians after the embarrassments of the mid-third century, a truly intimidating figure with the military mettle to match. As it happened, Maxentius used the walls of Rome, the propaganda value of representing Rome as well as bribery to defeat the invader. He then defeated his own father's attempt to oust him from power, all the more spectacular since his father had been emperor for more than twenty years. As Lactantius relates (On the Deaths of the Persecutors 28):
"After the flight of Galerius, Maximian, having returned from Gaul, held authority in common with his son; but more obedience was yielded to the young man than to the old: for Maxentius had most power, and had been longest in possession of it; and it was to him that Maximian owed on this occasion the imperial dignity. The old man was impatient at being denied the exercise of uncontrolled sovereignty, and envied his son with a childish spirit of rivalry; and therefore he began to consider how he might expel Maxentius and resume his ancient dominion. This appeared easy, because the soldiers who deserted Severus had originally served in his own army. He called an assembly of the people of Rome, and of the soldiers, as if he had been to make an harangue on the calamitous situation of public affairs. After having spoken much on that subject, he stretched his hands towards his son, charged him as author of all ills and prime cause of the calamities of the state, and then tore the purple from his shoulders. Maxentius, thus stripped, leaped headlong from the tribunal, and was received into the arms of the soldiers. Their rage and clamour confounded the unnatural old man, and, like another Tarquin the Proud, he was driven from Rome."
Unfortunately, when we think of Maxentius we tend to think of him as the man who lost to Constantine at the Battle of the Milvian Bridge, a man who was framed as a tyrant by the victor. But a look at the Basilica of Maxentius, his Via Appia complex and his epic restorations to Hadrian's Temple of Venus and Roma provides modern testimony to the clever the game that this man was playing.