There are some DLC
that I could do without. All those item packs, maybe the Warden's Keep and the Darkspawn Chronicles. But there is now one that you must
play after finishing the original game, and that is the Witch Hunt
The reason for that is quite simple: the original game was incomplete. Not in the sense that it was lacking, mind you. But the original story had one deliberately missing piece that kept bothering me ever since: the fate of Morrigan. Even if I've never considered romancing her, she is a good girl (well, you know what I mean) despite walking strange a path. And I sure wasn't ready to let her go with an "out of sight, out of mind" attitude.
Call me possessive, but I like to know what my party members are going to do when they leave. And with the blank spot that was Morrigan, I at least wanted to know that she is alright, that she'll do fine without me watching her back. And Witch Hunt
delivered just that. The DLC consists of five locations, new monsters, items, whatever, but for me, the only part that mattered was that final dialogue with Morrigan that should have taken place long ago.
That one piece of dialogue truly concludes the Origins
notwithstanding), and only after it is experienced is the game truly complete.