Sri Lankan tastes like a mix between Thai and Indian, but the best word to describe the cuisine, at least at Sigiri, a tiny pleasant restaurant, is DELICIOUS. I ordered the String Hopper Kotthu, small bits of rice noodle with chicken, egg, and vegetables. It is one of the most crave-worthy dishes I've had in awhile, and will come in handy warming my belly once the weather gets colder.
Everyone was equally happy with their meal, and with their BYOB policy and affordable prices (about $20 each with appetizers and entrees) it makes for an excellent deal too. You can make reservations online (which I highly recommend if you are in a larger group).