Savannah is cool. I spent a week there for work and got to enjoy downtown in the evenings. I think 5 days would be too long, but 2 days could be about perfect and a great time.
The town has a lot of personality. It is one of the oldest American cities and it was spared from the destruction of the Civil War that most of the South experienced. The houses, monuments, and general architecture give you the feeling that you are in another country. They do "ghost" tours, which are pretty popular with the tourists. The walking pub tours, rather than the bus ones, are the best. Most importantly, the food there is phenomenal.