I'll second the Cybook recommendation if the main use is going to be reading fiction.
And don't discount the Dictionary. I'm still surprised as to how often I use the feature, and I hardly ever used to actually refer to a dictionary in the past.
The Bebook might be a better option of you want access to more file formats and folder navigation NOW. Bookeen has said that Folder navigation is on their to do list, but that is no guarantee.
Finally, the Price is Stupidly good right now from WH smith, and you have the added advantage that if you don't like it you can return it to a high stree store for a full refund, an d then get the Bebook
