Personally, I'd shy away from Italian in Little Italy. VERY tourist trappy, and frankly, I dont find any of the food Ive had down there particularly remarkable. Id HIGHLY recommend Casa Mono on 18th and Irving, A mario Batali owned Spanish Tapas place. Not too fancy, not too pricy, but not cheap either. Somewhere in the middle. Great vibe, amazing food. Nearby is Bar Jamon, his tiny little charcuterie shop and it is equally worthy.
If you want to take your coworkers to what many consider the best burger joint in NYC, take them to Corner Bistro, a dumpy little bar with 2 dollar 50 buds and and a fantastic burger. Its on the Corner of West 4th and Jane. Down and Dirty, cheap, very local.
If youre feeling exotic, and want to check out a hipster Enclave, look into Fatty Crab, (a restaurant that I used to be sous chef at) Malayssian food. Sweet Hot Sour Spicy dominates. Tons of a great dishes, great SE Asian beers, lively atmosphere and in a hip neighborhood worthy of walking around after your meal. Its on Hudson, btwn Horatio and Ganesvoort
I would also recommend a new BBQ place that opened recently. Hill Country is texas BBQ done right, in a great setting. I havent had better BBQ in NYC.
Others to look into:
Shake Shack in Washington Square Park
Bao Noodles on 22nd and 2nd -great vietnamese food in a hip bistro setting
Dirty Bird to Go - 14th and 7th - Southern Fried Chicken and such
I personally LOVE chinatown, and would be happy to give you a couple places to go to down therre, but thats a little more detailed as some of these places dont even have names, I'd just have to give you detailed directions. But if youre not into down and dirty chinatown eating (and many arent) its not worth the novel. lemme know and have a great trip.