The unabridged edition on Of Prayer and the Christian Life, by John Calvin, is this month's free download.
I remember my first read-through of much of Calvin's Institutes of the Christian Religion, how surprised I was. Calvin has this rep for being an arid, abstract, almost rationalistic brainiac. What I read was nothing of the sort. It was the writing of someone with a deep and ardent love for God, with a big, Biblical vision that sees God everywhere and over all.
Institutes is a devotional!
I'll be downloading.