Yes been personally suspended for life for promoting how to build a boat ( a cb product ) and had the suspension over turned / account reinstated and have also helped to rebuild client websites that have been suspended by google and have had them reinstated.

The very first thing, is be nice to google or the hand that feeds you, no good getting upset, next put into place a path of repair if possible.

By that if you have purposely used G in a non productive or in a illegal type way with dodgy products and or services, then you chances or hope are very very slim to none of getting an old account back.

If you have been promoting a cb style / affiliate product and you account has been suspended then your ods of getting your original account back are slim to none but it may be possible under some circumstances, lightning hitting the same spot is probably more common. / this alone is a black spot and why people should be very careful about promoting another persons site in adwords, if it goes belly up you have no or little input into a resolution.

If you have just not understood or made a real balls of you own site and messed things up, then you need to work with google to further understand exactly what is wrong with that site and then submit it for re approval.

This often can mean a full rebuild and de hyping for better words of the account and can be a long painful process, but it can and does happen, if you have specific questions then that may make it easier to help you further.

Pete