What was the most influential battle in Roman history?

The defeat of Hannibal?

The slaughter of the Gauls by Julius Ceaser?

The overrunning of Rome by the Visigoths and Goths?

Well that was all equally influetial. But I would probably chose not listed ones, like battle for the town of Tarent, where the Roman legions were anihilated, but still won the outcome of the war. Tarent didn't have army, so he "purchased" one from Sparta, with the great commander known as Pear(not sure for spelling), where the Roman army lost a couple of great battles: Heracleie (280b.C.) and Ausculum(279b.C.), but won the final one in Benvento in 275(b.C.).
I could say much more but I would have written twenty pages.........
Also other.....

In your opinion then, which was better?

Well from listed I'd say defeat of the Hannibal.
But htey are all much of a influence.......
Did You know that Rome was overrun by Gauls in 387 b.C. And paid a big amount of money just to be free. The Romans were fighting bravely on the Capitol hill, they were fighting for weeks, but when they run out of food & dupplies................ The Capitol was saved by gooses of Yunona, Gauls succeded to pass guards and dogs, but gooses stopped them by alerting the city, people woke up and run to their weapons...... but after that as I said they run out of food......

the battle of the catalunian feilds mayby.