There are 21 rulers of Judah in 2 Chronicles and God's put them all on the throne. In fact, many of them have names that include God's name—"Yah," in Hebrew. All the names that begin with "J" or end in "iah" reflect that, like "Uzziah" ("God is my strength" ) and Abijah ( Yah is my father"). Despite their religiously symbolic names, we're dealing with a pretty mixed bag here. Let's try dividing them up like Clint Eastwood might—into the good, the bad, and the ugly.
Maybe it isn't fair to call this grouping of kings "bad." Maybe "inconsistent" is a better word. Their loyalties change and so do their fates.
He's pretty faithful for most of his life. This guy hates other gods so much that he even kicks his own mother out for worshipping idols. He has some victories in battle, but then he gets an alliance going with Aram. This does not make God happy. When Asa gets sick and doesn't "seek the Lord" (16:12), God lets him die.
He had a rocky start in life. He was almost killed by his grandma, but was whisked away to be raised in the Temple for seven years. Once he gets his chance to sit on the throne, this king restores God's house to its former glory. Later in life, he has a change of heart and "abandoned the house of the Lord […] and served the sacred poles and the idols" (24:18). After he kills the son of the high priest and is wounded in battle, his own servants finish the job and bump him off. No one's sad about it.
Uzziah did some good things like winning wars, building armies, and worshipping God. But then he has to go and get cocky. He barges into the Temple and demands to enter the special holy places reserved for the priests (and the spirit of God, of course). In the end, "a leprous disease broke out on his forehead" (26:20) because God sees this as a major violation of Temple protocol.
Manasseh starts out worshipping other gods, so God sends the Assyrian Empire to teach him a lesson. After he's captured and sent into exile as a prisoner, Manasseh has a change of heart. Maybe Yahweh is the right way after all. He begs for forgiveness and God gives it to him. All it takes is a little time in the slammer for him to figure out "that the Lord indeed was God" (33:13).
Again, we see the same similarities with the other greatest kings. When these kings are good, they're very good. They're worshipping God, getting rid of idols, taking care of the Temple, and winning wars. But when they're bad, that means idol-worship, distrust of God, and even murder.