When talking about the Fall of Rome, mention is always made of Gibbon's landmark contribution to the field, but Gibbon lived in the 18th century and saw the Decline and Fall of the Roman Empire from that perspective. Here is a collection of excellent 21st century popular studies of the Fall of Rome.
Also see the following review article:
"The Return of the Fall of Rome
The Fall of the Roman Empire: A New History of Rome and the Barbarians by Peter Heather; The Fall of Rome and the End of Civilization by Bryan Ward-Perkins,"
Review by: Jeanne Rutenburg and Arthur M. Eckstein
The International History Review, Vol. 29, No. 1 (Mar., 2007), pp. 109-122
Adrian Goldsworthy packs information about each of the emperors of Rome while showing that Rome fell slowly and as a result not of barbarians but internal problems, including incompetence and fate or chance. He even addresses the idea that perhaps there are already too many works on the topic.
In 2007, an English translation of Alessandro Barbero's 2005 The Day of the Barbarians
was published. Barbero blames the 4th century Battle of Adrianople and its aftermath for the fall of the Western Empire. After the battle, which was in the Eastern Empire, the successors of the loser, the Emperor Valens, managed to push the barbarians westward where they continued to look unsuccessfully for land and acceptance until they sacked Rome.
The Fall of Rome: And the End of Civilization
is by Bryan Ward-Perkins, who believes that Rome fell and rejects the idea that Rome ended without catastrophe or decay. Ward-Perkins refers anecdotally to an odd German book, Der Fall Roms. Die Auflosung des Romischen Reiches im Urteil der Nachwelt
, by Alexander Demandt, which contains "a compendium of verdicts on the fall of Rome." 400 of such verdicts occurred between 1800 and 1965. If you're interested in bizarre reasons, check out the list.
Heather's thesis is that the various assaults on Rome had ripple effects. Rome lost territory and revenue, was spread too thin militarily, and the barbarians on the border kept growing stronger. One attack was not enough, but the cumulative effect caused the fall of the western empire.
This choice is good for the general reader. It is a lavishly illustrated museum book written by excellent historical story tellers who relate the story of the Rome's fall beginning roughly with Diocletian's tetrarchy, and going through the aftermath of the Goth's sack of Rome to the death of Galla Placidia.