In my experience, people who are bipolar are the most likely to show remorse for lying -- if they are stable and on medication. Bipolar people tend to lie most when they are in a manic phase. When they come down, they usually realize they have lied and feel guilty for doing so.
Borderline personality disorder is another condition where sufferers may feel remorse for lying, again, if they are on their medication. Maybe it's the chemical imbalance that makes people with these disorders lie and feel good about it. When their brain chemicals are balanced, their consciences seem to click back into working order. It's a strange phenomenon to watch.