Check out the east village.There are numerous resturants in that area that are cheap,good and Trendy.There are great indian resturants on sixth street.FruiteDimare on 4th and second.Check out gayot.com or zagats.The east village is loaded with great bars and resturants.

If you like ethnic food, Chinatown has lots of cheap, good food options. You can easily walk around there and almost any place will fit your budget. 2 of my favorites - Nha Trang Centre on Centre St. for inexpensive and very tasty Vietnamese food (last week my boyfriend and I had 2 beers, split an appetizer, each had big bowl of noodle soup, including tip was $21.00 total). New Green Bo on Bayard street has great dumplings.
Dim sum is also a tasty cheap option. You can easily eat in NYC for under $20 a person, but along with other posters' comments, you need to stay away from Times Square/touristy areas.
I can go across the street from my apartment and pay $12 for a martini, but I can also walk 3 blocks to the local bar and get a pitcher of beer for $6! So don't just assume because one place is expensive, that you can't find a reasonable one just around the corner.

Hi!
If you want cheap here it is.
There is a Brazilian restaurant at which I always (for years) have been eating.
It has an odd set-up. If you eat at the bar you have one price. If you eat at tables downstairs you have another price, and if you eat upstairs you have still another price.
The bar section is the one I am referring to. You can get a modified salad bar and a choice of chicken, steak bits, fish, Brazilian dishes, regular steak with rice and beans and wonderful potatoes for between $6 and $8.
The Address is 123 West 45 Street (just West of 6th Avenue - Avenue of the Americas.) The name od the restaurant is Cabana Carioca.
Enjoy!
Judy

In Times Square I'd recommend Tad's Steaks for a great meal at a reasonalbe price. It's kind of a cool place because you choose waht steak you want and they cook it right in front of you while you're in line. The staek comes with a couple of sidedishes as well. You can definitely have a complete meal for about $10-15.

I love Shanghai Joe's in Chinatown. Dinner for 2 is under $20. For a cheap lunch or dinner, I love the H&H bagels. The bagels are fresh! A lot of the small grocery stores have buffets. I've had some tasty entrees at some of them.

We actually had a very reasonable brunch at "Dish" on Allen St. on the LES last Saturday. Complete brunch (mimosa/main course/coffee or tea) was $11. Various menu selections were around $7 a la carte. Brunch is served on Saturday & Sunday.