Character that had the most development, growth?
Chase - I really like how we got to see him sense S1, to be he was the one that had the most character growth. He starts as a kiss up and then slowly facing up to house, coming back to the team slowly not seeking as much approval, "stopped" dating so many women.. at the end he became known as the best surgeon, he was mature, bright, it was great seeing HIM take House's dept and not Forman whom I didnt think had much growth, he always loooked like he wanted to punch someone.
House himself, my favorite, beloved, extremely rational, brilliant, character ever... I loved how he's development wasnt linear, he had ups and downs, I can relate to him and his fight with sobriety.
There's others too but to me these 2 were the most expressive ones... Forman is the only one that to me had like zero development, he started with the same personality and ended the same, I wouldnt have liked seeing him being in House even the annoying student they had on the team had growth when she lied to the patients parents which went against everything she believed. (Masters)