In book three after Will and Evanlyn Princess Cassandra have been captured (at the end of the second book), Halt asks for leave to go and rescue them. When he's told no (the kingdom is in chaos after an attack) Halt basically goes and gets himself banished for a year ALL SO HE CAN GO AFTER WILL. And partway out of the Kingdom he runs into Horace who tells him he's (Horace) gotten leave from Battleschool (Knight training) to go with him.
What Halt did to get himself banished has two punishments, death or banishment. After hearing this the King (a friend of Halt's) laid down the sentence of a years banishment, using a loophole in the law that never stated a specified duration (despite the implication of the law being banished for life). Notably even the Chamberlain, who's duties include advising the king of the law, goes with it.
Two major ones occur in the sixth book. The first is when Will breaks the mind control on Alyss by stating that he loved her. The second occurs after what starts out as a downer ending. Will parts with the dog Shadow. Will isn't sure Alyss was in a state of mind to comprehend this declaration of love, and Alyss isn't sure if Will's declaration of love actually happened or was merely a dream. Will returns home, sad and alone with nothing going quite right, and after a few days he receives a letter from Alyss stating that she loved him.
Madelyn making Will laugh. He hadn't laughed since Alyss died,18 months before the start of the book.
From Book 12, "He (Will) began to laugh. And somewhere, the laughter turned to tears and he was sobbing uncontrollably—immense sobs that racked his entire body and floods of tears that coursed down his cheeks. And he knew the tears were the ones he had never been able to shed for Alyss. They were for her. And they were for Maddie. And they were for him. Most of all for him."