How do you Eread?

With an open platform like Android, there are many choices when it comes to Ereading apps/stores. From the world famous Amazon Kindle store to the Free Project Gutenburg, there are many places to look. With all theses places crowding the market, prices have become very competitive between them all.
Recently, I have found myself puzzling over which store to go with. Should I buy from Amazon, or ex-Canadian Kobo (Now owned by Japanese Rakuten)? Google Play Books looks good, but as good as Sony's selection? Each have their advantages and disadvantages. Most all of them have accompanying E-ink readers, except Google, of course. However, they all seem to allow syncing between books.

With so much choice, it can be a bit overwhelming. What do you all use, and why?