If you want a top-line ereader, go with one of the Kindle ereaders.  However, if just a basic ereader will do, get a Nook Simple Touch. It's quite cheap now, plus it can last a long time between battery charges.  I've had a Nook ST for 3+ years, and it can get pretty close to a month between charges, depending on level of use.  Screen resolution is less than on more modern Kindle readers, and it is NOT back-lit, but otherwise, the Nook ST should handle all your basic ereading needs.  It is completely readable even in direct sunlight.  It's light and durable.  I have mine in a soft case to give it extra protection from accidental drops.