My vote goes for a 1:6 scale Marion Ravenwood. I want Sideshow to make her in her red and white outfit she wore during the fight in the streets of Cairo, and make it come with the white dress Belloq got for her. Indy needs the "love of his life" by his side...in my opinion.
For some reason that red/white outfit has been the one that toy companies seem to constantly release.
Personally, I'd prefer her in that white dress Belloq gave her -- she wore it though the best section of the movie (Well of Souls trap, plane fight). I'd also prefer a ripped and tattered version like this: