Scott Hahn is a former presbyterian who "Poped" about 15 years ago and has become a leading lay apologist for the Catholic church. I am a Catholic-friendly Protestant and find his works interesting. There are some assumptions and conclusions I can't go along with, but there are many areas of commonality that I would not have expected, as well as areas of faith and practice that speak strongly to me.
His works that I have read are: Hail, Holy Queen, about Mary, who I absolutely love; The Lamb's Supper, which ties the Mass to the Book of Revelation; and Lord Have Mercy, a work on confession.
There are about 10 more, many of which I expect to read in the next few years.