i will second boccalupo's suggestions of wichcraft & dishes. both can get pricey though. bread and olive is good. there is also a crisp on 40th & b'way i believe-inventive falafel pita's.
to add for your midtown deli's there is duke's on 41st and zeytinz's on 40th. both are nicer then your generic deli with options of all cuisine's.
are you looking for something specific? there so many options in the area. if you go to 42nd btwn 5th & 6th you have hale n hearty, pret, cosi & chipotle alone.
Right in Bryant Park there is 'wichcraft, good but a bit pricey and usually a bit of a wait.
On 36th btw. 6th and B'way there is Macaron Cafe, which makes nice sandwiches on French baguettes and macaron cookies.
On 45th btw. 5th and 6th there is Bread and Olive. Lebanese fare. Also on 45th between 5th and Madison is Dishes, which does a good job with upscale, cold buffet salads. They have other things as well. Very good and fresh, but a bit pricey.
On 41st btw. 5th and Madison there are a few Japanese places that do takeout sushi and other items. My sushi eating friends seemed to say it was pretty fresh and tasty at lunch.
On 8th Ave. near 40th is Pick a Pita which makes a nice falafel.
On 6th Ave. between 44th and 45th there are several kosher (Moishe's) and halal food carts, some of which are pretty good.
And if you like your namesake dish, you can get a fix of soup dumplings at Evergreen Shanghai on 38th btw. 5th and Madison.