Some highlights for me:
Velen after the attack on the Exodar, mourning his son and deciding enough is enough.
The final scene with Runas the Shamed.
In Dreams back in Vanilla.
The unmasking of Onyxia in Stormwind. Though I think the comic retconned how this went down.
Running into the Lich King during that shaman spirit realm quest thing in the Howling Fjord. One of the pre ICC moments where the LK had some actual menace and a show of strength rather than just siccing an easy to kill mob on you or taunting you and leaving. An easy to miss moment but a great one. Though I suppose the ‘I was once a shaman’ line doesn’t really ring true anymore, there seemed to be some confusion on blizzard’s end back then how much of ARthas vs Ner’zhul was in that helm.