I would want one that adds a massive piece of land like an island or part of a region. That and ownable castles

I don't know yet if you will be able to use certain materials from dragons and make armour/swords/potions/decoration with it. But if this won't be available when the game get released then I would like to see something like this happening. Then I will be a very happy man

New land. Shivering Isles was much more fun than Knights of the Nine, because it simply added something new. Western mainland Morrowind would be one way to go. Atmora would also be possible as I can't recall its destruction.

I'd like to see the game, then decide what needs to be added once I've got half a clue what I'm adding onto.

Regardless of how great the game may be, new content is something we can all enjoy. (well... maybe not horse armor)

Anyways, ideally I would want something that adds new land. Shivering Isles was amazing, and was a great contrast to the sometimes bland Cyrodiil. Unfortunately I don't see them doing another big expansion like this, based on their comments. Also based on the DLC available for FO3, most of them were fairly small. I think they'll do this to get the most $ out of us. Make it just big enough to cost more than small DLC like spell tomes etc, and smaller than a full blown expansion so they can put more out there.

I like all of those expansion ideas (minus the second to last) but the game isint even out yet...so I can't really tell what I would want yet

Shivering Isles but with a different Daedric Prince.

I have a couple of threads pertaining to this subject
http://www.gamesas.com/index.php?/topic/1175215-blacklight-expansion/page__p__17360400__fromsearch__1#entry17360400
http://www.gamesas.com/index.php?/topic/1174502-future-skyrim-dlcs/page__st__20__p__17353990__fromsearch__1#entry17353990
http://www.gamesas.com/index.php?/topic/1182190-blacklight-expansion-thread-2/page__st__20__p__17538507__fromsearch__1#entry17538507
http://www.gamesas.com/index.php?/topic/1182739-expansion-or-dlc-locations-2/page__p__17539261__fromsearch__1#entry17539261

I want expansions to that of morrowind, Well thought out expansions and not scabby DLC Cons.

Expansions that not only add unique landmass and new quests but unique items... like bloodmoon and hircines ring... Although i hope you can be a werewolf in skyrim in the vanilla game or atleast fight them and then be one in an expansion.