Which class for achievement hunting?

Hi everyone. I apologize if it's not the right section. I mostly play solo on wow and i enjoy achievements very much but everytime there are noone doing old raids/instances for achievements. I wanted to do it with a solo class but i don't know which one to choose. I know DK is the best but sometimes i have to go afk and i don't like being killed from respawned mobs or gankers so i will maybe try out with a rogue or druid for save stealth mode for when i am afk. So, which of these classes you think is better? Is a rogue good for soloing and achievements hunting? or maybe better go with a druid that has a stealth mode too? Thanks

I would say druid, you got good defencives, good damage and self heals.

All-round i would say dudu it has a lot of utility. But if you plan on doing solo bosses nothing does it like a DK.