Tavros is my patron and favorite as a person, but his story is underdeveloped as yet. Vriska's story is my favorite troll story. Even before she admitted her secret insecurities, I saw the genuine concern mixed with her sadism.
I also dig Eridan and Equius though. Creepers yeah, and too weak to overcome their flaws, but interesting characters. The troll arc needed deadly threats from within (Eridan, Gamzee) not a sappy ending where they all develop their inner humanity and throw a party. I hated that Equius failed, but only because it was a perfect opportunity for moirrailship to save him from himself.
Gamzee... I don't know where his character is going. I just like PB&J.
Edit: About Eridan, I think his genocide-spiel was all BS. He admitted to himself that he could selectively kill the land dwellers just by a little bit of inaction (letting Feferi's lusus go hungry). Feferi calls him out on being friends with the other trolls. He was just trying to live up to his blood, like a lot of the villainous trolls. He got dumped, he got turned down by every flushed romance he Hoped for, but he kept trying... until nobody even feared him. That's when he snapped, because he WAS powerful and deserved at least to be feared.