I also think this is a different topic... although, if so, it would be rather sad thread...

The moments people posted here are very good, but my "favs" are different. First, is the moment from the same episode Suusje mentioned, when Lisa is sitting in her room with saddened look and Michael and Bart are watching her from outside. Michael says: "She's looking sad." Bart replies "That's because she knows we're looking at her." Then Lisa... oh my, she turns to them and calmly says: "I know that you're looking at me, but I would look the same even if you weren't." ..... I wish I could hug her that moment.

Another moment is the scene when Murphy has died and Homer tried to cheer Lisa up. See attachments...