Quotes from Josephus concerning Giants www.generationword.com
Get access to the entire text of Josephus here
"For many angels (11- 
  This notion, that the fallen angels were, in some sense, the fathers of the 
  old giants, was the constant opinion of antiquity.) of God accompanied 
  with 
  women, and begat sons that proved unjust, and despisers of all that was good, 
  on account of the confidence they had in their own strength;
  for the tradition is, that these men did what resembled the acts of those whom 
  the Grecians call giants."
"These kings had laid waste all Syria, and overthrown the offspring of the giants. And when they were come over against Sodom. . ."
"They told them also, 
  that they found at Hebron the posterity of the giants. Accordingly these 
  spies, who had seen the land of Canaan, 
  when they perceived that all these difficulties were greater there than they 
  had met with since they came out of Egypt, they were aftrighted 
  at them themselves, and endeavored to affright the multitude also." 
"For which reason they 
  removed their camp to Hebron; and when they had taken it, they slew all the 
  inhabitants. There were till then left the 
  race of giants, who had bodies so large, and countenances so entirely different 
  from other men, that they were surprising to the sight, and
  terrible to the hearing. The bones of these men are still shown 
  to this very day, unlike to any credible relations of other men. 
  Now they 
  gave this city to the Levites as an extraordinary reward. . "
"A little afterward 
  the king made war against the Philistines; and when he had joined battle with 
  them, and put them to flight, he was left 
  alone, as he was in pursuit of them; and when he was quite tired down, he was 
  seen by one of the enemy, his name was Achmon, the 
  son of Araph, he was one of the sons of the giants. He had a spear, the 
  handle of which weighed three hundred shekels, and a breastplate
  of chain-work, and a sword. He turned back, and ran violently to slay [David] 
  their enemy's king, for he was quite tired out with labor; but 
  Abishai, Joab's brother, appeared on the sudden, and protected the king with 
  his shield, as he lay down, and slew the enemy. Now the 
  multitude were very uneasy at these dangers of the king, and that he was very 
  near to be slain; and the rulers made him swear that he 
  would no more go out with them to battle, lest he should come to some great 
  misfortune by his courage and boldness, and thereby 
  deprive the people of the benefits they now enjoyed by his means, and of those 
  that they might hereafter enjoy by his living a long time among them. "
"When the king heard 
  that the Philistines were gathered together at the city Gazara, he sent an army 
  against them, when Sibbechai the 
  Hittite, one of David's most courageous men, behaved himself so as to deserve 
  great commendation, for he slew many of those that
  bragged they were the posterity of the giants, and vaunted themselves 
  highly on that account, and thereby was the occasion of victory to the Hebrews." 
  
"They had a man who 
  was six cubits tall, and had on each of his feet and hands one more toe and 
  finger than men naturally have. Now the person 
  who was sent against them by David out of his army was Jonathan, the son of 
  Shimea, who fought this man in a single combat, and slew him; and 
  as he was the person who gave the turn to the battle, he gained the greatest 
  reputation for courage therein. This man also vaunted himself to be 
  of the sons of the giants. But after this fight the Philistines made 
  war no more against the Israelites."