Although Scipio Africanus was the most notable, most of the the Scipio leaders were good generals but there are to many good generals of Rome to mention all of them in a top ten list of Roman generals. But in my opinion they were the the Roman equivalent of the Barca family of Carthage (Hannibal) and thus only fitting that one of them should beat the greatest Barca and possible the greatest general ever, the Scipio in mention will appear later on down the list.
Restored Roman authority in Germanica together with Tiberius after the disaster at Teutoburger Wald. Conquered Cappadocia and Commagena (in Asia Minor) in the few years before his death.
Actually not a Roman but a Byzantine general. The only one who conquered Rome and Carthage: thanks to his skills the Byzantines restored their power in Italy for a few centuries.
Often underrated, Sertorius managed to survive in Spain for nine years, defeating Pompeius Magnus and winning the hearts and minds of the locals with his skills as statesman and diplomat. The fact that he defeated Pompeius and was nicknamed ‘the new Hannibal’ says enough.
As adopted son of Nerva, he became emperor after Nerva’s death in 98. While most emperors appointed skilled proconsuls or family members to lead the legions in person, Traianus led his men in person against the Dacians and Parthians.
In a century of giants, Caesar was the greatest. With political skills he rose to the office of consul, and as proconsul he conquered Gaul in a swift military campaign. During the civil war, he fought against the odds most of the time.
Very skilled and calculated general although mainly known for his political leadership he won some very convincing victories against hardened warriors such as Mark Antony.
Marius made what what we consider the Roman army. His skills might not necessarily have been in tactics but more in the training and conditioning of his army.
Constantine reunited the empire and brought it back from the brink of destruction, if only for a few more years. Nevertheless, in politics and on the battlefield he was brilliant.
Scipio Africanus was the roman who saved Rome from Hannibal by studying Hannibal’s every tactic, without him the empire might never have happened. In a sense he made this list possible therefore deserves to be number 1.