If you've had periods of unemployment as a result of redundancy, I'd be inclined to just list the years, rather than the months as redundancy and temporary unemployment is a fact of life thee days. If however, you've been sacked several times and then unemployed you will have to decide how you explain your "reasons for leaving" if asked.
If your creer gaps have been caused by spending time "In Her Majestry's Pleasure", you will have to be honest as lying to an employer may well constitute a reason for sacking.