I guess it's fair to say that in Judges 8, we see a fair bit of Gideon's bad side. Clearly the man is a good military leader, but not a real "people person". Well, in general; he does manage to flatter some of the men of Ephraim enough to get them to lay off criticizing him.
Other than that, though, we're not really seeing the best of Gideon as he threatens to beat up the men of Succoth and tear down the tower of Penuel. After he finishes his military campaign, he does that and more. This is an unfortunate tendency particularly among Middle Eastern peoples, and really mankind in general: the tendency to view things in stark black and white, and declare that anyone who does not ally with you must therefore be your mortal enemy. This is an attitude not endorsed by the Bible, but often observed by it.
There's also a little vignette in which Gideon tries to get his son to do some killings, but his son isn't willing to do it. Honestly, I'm not sure what to think of this. On one hand, once again this is wartime, and the context shows that the men were killers themselves, and therefore may have fully deserved the death penalty. On the other hand, I do wonder how old this son was, as the Bible never says specifically, and what exactly was going through his and Gideon's mind. What sort of a man is Gideon, that he wants his sons to do his killing for him? Why does he have 70 sons, for crying out loud? Actually, the thing about 70 sons from "many wives" is that the time frame is not stated, but you might wonder if most of these wives and children came after the military conquest. Is Gideon taking advantage of his status as a celebrity? (My comments on polygamy here.)
Actually, there is an offer made to Gideon to become king of Israel, but he turns it down. Instead, he asks for a share of the plunder from the battle, and uses it to make a fancy shirt. This turns out to be a bad thing, because for some reason, people seem to start to worship the shirt like an idol. The one really good thing Gideon does is try to turn people back to God, but he somehow ends up doing the opposite in the end for many people.