Swagat Indian Restaurant is the best Indian food in Madison, hands down. Friendly staff, an extensive menu, tantalizing aromas, delicious foods, and good prices all combine to form an amazing dining experience. Their naan is wonderful, their poori is a heavenly pillow of fried dough, and the lamb biryani is the best I've ever had, anywhere.
I've also eaten at their lunch buffet, which has a great variety of foods and is kept fresh because of constant replenishment.