Some communities and building types have held their value better than others. For example we know that generally condos have taken a much greater hit and are slower to recover than single family homes.
This is similar to asking someone what the best car is. There is a lot that has to be taken into consideration but would speculate that a range of 20-50% would cover it.
As a potential buyer, we recommend focusing on today's market by becoming as familiar with it as possible. This will help you to be able to identify value and opportunity, equipping you to be ready to move quickly when the right opportunity presents itself.