If you got hit by Google Panda or Google Penguin, I think it is best to create a new domain instead of spending many hours trying to clean, remove or fix your previous back links, it could be even thousands of back links to remove if you were automating your back links.
In some case it might be really wise to start over, but its different from case to case. But creating some usefull unique white hat minisite aside of blacklisted web might be good idea i think
See instead of creating a new domain, we can create a backlink to regain that penalty because after creating a new domain we should create a backlink for that then it is also a time taken right