Another great lunch place I go to often here in Midtown East is Oms b Rice Ball Cafe (the name is supposed to replicate the phonetic pronunciation of "omusubi" in english). This cafe's main staple are the onigiri, although they do have some noodle dishes.
What I love about this place is the variety and creativity of the onigiri. Each onigiri is carfully put together and made with fresh ingredients (which might explain why the prices at Oms b are not particularly "recession friendly"). There is so much variety that standing in line is always torture as I agonize about which onigiri I will pick for lunch.