30 Day Grey's Anatomy Challenge - Day 25: Saddest death. Now, I'd normally say George, but after the season 8 finale, I'd have to go with Lexie. Maybe because of the dialogue between her and Sloan. Maybe it was her "You're a disease. I'm infected by Mark Sloan" speech. Maybe it was the way she said "tell my sister I love her" line. It was just sad. It also leaves Mark sad and that makes me sad.