As I'm not in the U.S. the selection of ebook readers I can choose from is as follows:
-Amazon Kindle 5 ad-supported
-Barnes & Noble Nook Simple Touch (I've tried this one in a store - was OK, little bit worried about not being able to change font size and text reflowing while reading a sample PDF)
My budget is unlimited. I'm willing to pay more if there's something in an ebook reader that I absolutely need. Read: I'll pay more for a Sony PRS-T1/2 for the openness, if worth it.
-Must have a memory card slot or some other way of getting content onto it
-Must have good (read: I'd prefer if I could change e.g. font size) PDF support
-Must have an e ink screen
My reading will be limited to plain text inside PDF (fiction mostly - no academic papers). Also, I will only be reading at home, so touchscreens are fine, though I have nothing against regular ones.