Tanking Mythic Argus was quite unique as you had to plan your own death and you could kill your own team if you survived too many scythe swings or if you didn't survive enough of them. I ended up dying like 3-4 times per fight counting the normal death everyone goes through.
Jaina (heroic) was super cool with a ship fight at the start and then the iceberg phase where you can't see and have to avoid freezing lol. It also was very cool thematically and storywise, where you play as horde even if you're alliance. She also did cool stuff like ice blocking whenever you cast BL.