I know there is a Quest one, but I don't know if there is an Achievement one, pls redirect em if there is.
I have been currently working on the Loremaster Title and it came to mind what my favorite Achievement(s) are:
They could be ones that were easy to get,
Gave epic movies (Veteran or Wrathgate)
Or free items
A few of my favorites are the Veteran of Wrathgate, When I got my Epic Flyer and Friend or Fowl? (I'm killin da tuwkeys for an acheevmant)