Personally, I enjoy reading about recovering evolutionists far more than debating: I found these:
Emeritus Professor Tyndale John Rendle-Short - From (theistic) evolution to creation
For Prof himself, educated at Cambridge and brought up with his father's writings, theistic evolution (or its variant, progressive creationism) was the natural direction for him to take. His odyssey to being chairman of one of the most effective creation science outreach ministries in the world was overseen by the Lord's hand in countless ways, both large and small.
Charlie Lieberts - (Chemist)
Charlie Liebert’s idea of a good time back in New Jersey was to drink beer with a bunch of buddies and mock Billy Graham on television. A self-described “atheistic evolutionist,” Liebert would ridicule the fact that he and his friends were “sinners.”
Dr. Gary Parker (Biologist)
"I was very consciously trying to get students to bend their religious beliefs to evolution."
"Evolution was really my religion, a faith commitment and a complete world-and-life view that organized everything else for me, and I got quite emotional when evolution was challenged." Dr. Gary Parker's testimony as to how he went from teaching evolution at the college level to being a leading spokesman for Biblical creationism. - See the full story at From Evolution to Creation: A Personal Testimony
Dr. D. Russell Humphreys (Physicist)
While neither of the two links we have for Dr. Humphreys states that he was a former evolutionists and atheist, we know this to be true from a 1999 debate he participated in at Harvard University in which he stated these things. See this interview with Dr. Humphreys at: Creation in the Physics Lab.
Dr. Alan Galbraith (Watershed Science)
"I attended a creation seminar arranged by my pastor. I had only been a Christian for some four years or so, and was still a convinced evolutionist. I have to admit that I went with the attitude — what can this pastor, whose last science course was probably in junior high school, tell me about the area I know so much about?" See Recovery from evolution (Alan Galbraith interview)
According to modern evolutionary theory, our planet originated from the accumulation of hot, gaseous material ejected from the sun, and the Precambrian granites were among the first rocks to form during the cooling process. University science courses convinced me that the evolution of the earth was just a part of the cosmic evolution of the universe. As a result I became a theistic evolutionist. Years later I began to re-examine the scientific basis for that decision. My thoughts turned to the age of the earth and the Precambrian granites. Were they really billions of years old? See Dr. Gentry's Book Overview . See his web site at Earth Science Associates .
Tulane University

Dr. Richard Lumsden (1938-1997) was a professor of parasitology and cell biology at Tulane University in Louisiana where he also served as the dean of the graduate school of biological sciences. During his illustrious career, Lumsden published about 90 peer-reviewed papers and was awarded the Henry Baldwin Ward medal (the highest world-recognized award for parasitology ). He also received over 21 research grants and contracts from many well-known organizations such as the National Institutes of Health, the National Science Foundation and the United States Food & Drug Administration (FDA).
In the YouTube video below, Lumsden (a self-proclaimed evolutionist and Christian ridiculer) relates that after giving a lecture at Tulane University on the theory of evolution, one of his best students began asking him questions about evolution which he later realized had caused him to doubt his long-held evolutionary worldview . The doubts set Lumsden out on a search for truth. In his video testimony, Lumsden tells how he came to believe in a Creator and eventually walked up the isle of a church to accept Jesus Christ as his savior.
See video here
http://www.youtube.com/watch?v=s91-ABJ49ho#t=382
In his testimony, Dr. Lumsden says he was a staunch Darwinian evolutionist who took great pleasure in ridiculing Christian beliefs during his university classroom lectures. After the Louisiana legislature passed a law requiring pre-college teachers to give creation equal time with evolution in the classroom, Lumsden became so outraged that he prepared and delivered a lecture at Tulane University in support of Darwinian evolution. After the lecture, one of Dr. Lumsden’s top students asked to meet with him so she could “get some of her facts straight.” During the meeting, without being judgmental or argumentative, the student (who was a Christian) began asking Dr. Lumsden a series of questions about evolution. Three hours later when the student thanked him and walked out of his office, Lumsden realized the student’s questions had left him with a lot of doubt in his mind about the theory of evolution, a theory he had wholeheartedly embraced for many years.