Something worth mentioning, I feel, is a perception that Aemon would be the best king of any of the immediate heris. However, I think that's a pretty profound misreading of Aemon's character.

It's true that he's undeniably the most accomplished and overall competent prince in the show. He's the best dragonrider, either the best or second best duelist (after Daemon), and probably the most academically accomplished. He's undeniably better then his brother Aegon?

But he'd probably still be terrible at it.

More then any prince besides his brother, Aegon is consumed by his vices, and his vice is worth. He's cruel, callous, vengeful, remembers slights, and isn't especially loyal. He's jealous to a fault, to the point where it consumes him. We see how much his inferiority complex consumes his behavior at various points.

What's more, a lot of the events of the show have been driven by his lack of self-restraint. At basically any point in the story where the characters had an opportunity to pull back (such as episode 8 and 10) it was his actions that prevented it.

As King, Aegon would preaide over a reign of terror. Competently managed and temperate, but vengeful, vindictive, and quick to use power to punish lords and small folk who he feels slighted by.

Competence is only a posative quality when it's directed at posative aims.