First: I regret that they killed Lee at the end. I liked playing as Lee. More than I do playing as Clementine. And would've preferred to have kept playing as Lee.
Second: I regret when it came to Lee getting bit, that cutting his arm off didn't do anything. For to it to have saved him, it needed to be cut off instantly. If cutting it off would just bought him a little more time, like maybe a few days, I'd have been happy.
Third: I regret that Ben died in episode 4, just to see him die in episode 5. Even though it was the right thing to do, it still kind of felt like: "What's the point?" I was wanting him to live, to make things right. And was curious to see what kind of person he'd be in season 2.
Fourth: I regret Carly getting killed. She was a decent character. One of the few, next to Lee, Kenny, and Chuck.
And fifth: I regret Chuck being killed off. And so quickly! I liked the man, I though he had a goodness about him. I was also wanting to see him in season 2. I would've actually preferred him to have been the PC character for this season, instead of Clementine.