The character development, I'm surprised at how good it's getting. Not to mention, the fight for the Seven Vongola Rings gets more and more interesting.
Ryohei's fight was kinda meh, but he figured out how to beat his opponent easily, especially thanks to Kyoko. Surprised he got his signature scar near his left eye from defending her when they were kids.
Lambo, don't die. Man, just when 20 year old Lambo was about to defeat his opponent, the 10-years bazooka's effects wear off, and Tsuna has to step in to save him from certain death, and by doing so, he got the Sky Ring taken away (Due to interfering with the match.). However, he valued his allies' life more than the rings.
Gokudera's battle so far was the most interesting one by far, with how he figured out his opponent's tactics, and managed to defeat him, but he failed to get the other half of the Storm Ring from his opponent before the library exploded due to the 15 minutes being up. Tsuna got through to him it's not worth dying to get the ring, and he just handed it to his desperate opponent, and ran off to live another day instead of dying with him, and the Storm Ring being destroyed as a result.
I'm really wondering how Yamamoto is going to be able to defeat Squalo (Especially since Squalo has already beaten people using Yamamoto's sword-technique.), who apparently was supposed to be the Varia boss, not Xansus. Oh how I wonder how Xansus, Vangola IX's son came into power. Things will get very interesting.