Not exactly breakfast, lunch, or dinner, but I love Purity Ice Cream in Ithaca, down by the farmer's market. For lunch/dinner, I've always enjoyed my meals at the Glenwood Pines, a bar/grill overlooking the west side of the lake about 3 miles north of town. The Pinesburger is excellent, as are the fish and steak entrees. http://www.glenwoodpines.com/new/. And if you're in Ithaca on Saturday, go to the farrner's market. Lots of good things to eat and buy.
1213 Taughannock Blvd, Ithaca, NY 14850
IC is located in the part of Ithaca known as South Hill. The only places very close to campus are Rogan's, a sandwich shop that caters to the students, and Sunset Grill. To get downtown, where there are many more options, take a right when you leave campus and simply keep going straight. 96B turns into Aurora, which is one of the main streets downtown.
I don't go out for breakfast too often, especially not through the week, which is when I'm guessing you'll be here, so I don't have any recommendations. There are a few diners downtown, but I haven't tried them yet.
I like Moosewood (probably Ithaca's most well-known restaurant) for lunch rather than dinner. The prices are more reasonable for the portion size, and there's always a good variety. If you're looking for a quicker lunch, I suggest Collegetown Bagels on Aurora or Ithaca Bakery on Meadow Street.
For dinner, it depends on what kind of cuisine you're interested in. There are a lot of options downtown. Some of my favorites are Madeline's (Asian fusion cuisine, but they're best known for their incredible desserts), Just a Taste (tapas), Sushi o Sake, and the Bandwagon Brewpub. Bandwagon is a fairly new restaurant, and what I like so much about them is that they use local ingredients where possible.
I'm not a fan of Viva Taqueria or the Ithaca Ale House, both on Aurora. I've had some very good meals at Viva, but also some really lousy ones, so I'm wary of recommending it to anyone. The Ale House is overpriced and usually very loud, and the service last time I was there was so bad that we actually left.
Hopefully you're here on a day when it's not too cold. Downtown and the Commons are nice to walk around in and will give you a feel for the town.
215 N Cayuga St Ste 70, Ithaca, NY 14850
400 N Meadow St, Ithaca, NY 14850
101 N Aurora St, Ithaca, NY 14850
For a nice breakfast in Ithaca you might try the Carriage House on Stewart just off Buffalo (this is on the hill up by Cornell). Haven't been there in awhile, but they have some nice baked goods and serve decent (Gimme!) coffee.
Carriage House Cafe
305 Stewart Ave, Ithaca, NY 14850