M.R.
It isn't a Bible study, but I love My Utmost for His Highest and Streams in the Desert. They are daily devotionals. I also love re-reading Hannah Hurnard's (spelling?) Hinds' Feet on High Places. I just found my copy and want to re-read it.
I was going through Calm My Anxious Heart with a friend online and really liking it (we live several states apart). I also bought a Women's Devotional Bible in NIV published by Zondervan. It has very nice mini-devotionals, inserts, and reading plans.