Here are some other good ones I have read, or that were recommended to me by relationship councilors over the last while. Some have some good scientific facts, others add a little humor, but they are all helpful:
His Needs, Her Needs How to affair proof a marriage - by Dr. Harley (works for marriages that arent in an adultry situation too.)
How To Hug a Porcupine: Dealing with Toxic and Difficult to Love Personalities - Dr. John Lund
The Case for Marriage- Linda Waite and Maggie Gallasker
Avoiding Emotional Divorce - Dr. John Lund
Hope for the Separated: Wounded marriages can be healed - Gary Chapman
Marital Relationships Seminar - Douglas E. Brinley
Why Men Don't Listen and Women Can't Read Maps - Barbara Pease
Why Marriages Succeed of Fail: And How you can Make Your's Last - John M. Gottman
When Men Batter Women: New INsites into Ending Abusive Relationships - John M. Gottman
The Marriage Clinic: A Scientifically Based Marital Therapy - John M. Gottman
M38, H37 S3, S7 Together 15 yrs Married 8 yrs Bomb July 2008 Inhouse separation "I hate you" "We are over" (too many times to count) Reconciled Sept 2009 (still worth it)