Convenient and fresh, What A Bagel has a simple but good selection of bagels and all that you could want with it. They get crowded on the weekends, though.
Haiku is one of the new sushi places in the area, but has attracted a very good sized crowd. the atmosphere is tasteful, and the food is good. The service is a little too much though.
Toyo Sushi is one of the best sushi places in westchester. They have reasonable prices, amazing quality fish and entree dishes, and a nice staff to go with it!
Famiglia has great pizza, but gets very crowded on the weekends. They are a White Plains staple, and are worth checking out, but be prepared for a wait!
Aroma is a small cafe in the heart of town. They have a great selection of coffee beans that they sell, as well as pastries etc. Their smoothies are the best in town.
Avenue Bagel Cafe is right in downtown Mamaroneck and easily accessible for a quick bite to eat while out on the town. They have shorter hours than many of the places in the area, but thats the only drawback.
Hunan Larchmont is a great place to go before or after the movies. They have a casual but nice atmosphere, and delicious cuisine. Typical menu, good quality.
I've been going to Luke's for years, and it is by far the best place in the area for Chinese food. The staff is phenomenal, and the service is fast and polite!
Bagel Zone has great fresh bagels and all the fixin's to go with it too. They have doughy warm bagels that are fresh and fantastic, especially with hot cocoa!
Stay away from here during 11-2, when the high schools population takes over, but after that, its a great place to grab a sandwich. The staff is super patient.