Pondicherry, Ooty & Kodaikanal.
If you are interested in temples then
Mahabalipuram or Mamallapuram, Kanchipuram, Vellore, Chidambaram and other places are there. http://www.tripoto.com/profile/monikachowdaryswarna I have been to a 4 day road trip from Chennai to Kanyakumari. You can visit trip details in my blog.