Here's where we're staying at the moment. Hotel Mahabs. It's pretty good, but unless you're always in the pool, endlessly snacking on the forgettable fare on offer in the restaurant, the INR 1,750 price tag on an A/C Double Room is not worth it.
Here are the details of Hotel Mahabs in Mamallapuram (Mahabalipuram):
Unit of Vinayak Cottages
Tel: +914427442645, +914427442643
Mobile: +919444283695 , +919283134671
#68, East Raja Street, (Behind SBI ATM),
Mahabalipuram - 603 104, Kanchipuram Dt.,
Tamil Nadu, India
I'd say come to this place if you didn't really find anything else. Will let you know when I try out the pool.