I would like firstly NO starforce or other such nasty hassle.

I would love a pocket plane/separate universe realm/personal space to escape to via an item say. It could be customisable with items you find throughout the game and/or purchaseable items. I like the idea of getting a mirror to decorate it and going to other universes through it. Having assistants there to help me and generally being able to customise a LOT. Somewhere more interesting than a house.

I would love the game to work on linux especially.

I like a lot of varied and interesting customisable items and clothing/armor. I love shopping. I like to have pets in game also.

Great storyline is good too as is voice acting. If you can get Stephen Russell who did a lot of voices in the Thief series you'd have the best - he is awesome.
Atmosphere is very important and probably hard to create in a game but it has to have a strong vibe to it that defines it as separate and distinct from all the mindless rpg fodder out there. I think a strong creative vision led by just a few people who have strong and distinct ideas works best as long as they know what they are doing.

I like to have NPC interaction a lot and relationships of various types. Guilds are good. I tend to like sneaky characters and to me a thief should be a thief if there is such a class. Only the thief/rogue should be allowed to pick open certain things. Not every container/lock should be smashable or the thief is just a weak fighter which is pointless. In this respect I was mortified with Neverwinter Nights (though I certainly love the game in many other respects).
I like secrets and hidden areas and easter eggs. I love in Divine Divinity that there are things hidden all over the place. It made me explore every last nook and cranny and is very enjoyable.

I don't care what developers/publishers say I like long games and this might not be do-able, (I don't know) but knowing I have 60 hours of fun ahead of me which will bond me to my character is a plus.

Thanks for all you have done so far