If your into smaller designer labels then the east village (Ave A to Cish) and nolita (north of little italy) have very good shopping.
We just went to see a really good musical (and we are not into musicals) called spring awakening, i would highly recommend it.
Food wise: several places have already been mentioned so i wont repeat but here are some more: if you want menus at any rest in NY go to menupages.com
Devi in Union Square has grt Indian food, as does Tabla.
Hearth in the East Village is very very good, Piccolo Angelo in the West Village is FANTASTIC and the ambiance is wonderful, there is usually a line outside, esp during the weekend so if you can go during the week thats prob best, they started taking reservations recently so you could try that as well but they are still mainly walk in. Mary's Fish Camp in the WV is also very good. Lower East Side is grt for drinks, food, and just walking around. There is a place called Inoteca on Ludlow that I love to just grab a drink and something to snack on. Grt menu.
If your a jean freak there is a place called Atrium that carries a very good selection, its on Broadway north of Houston, then there is Lounge also on Broadway south of Houston. Bloomingdales in soho carries some edgier stuff then the one uptown. Good Chloe bag selection...West Village is also good for shopping, Christian Louboutin has a boutique there and there is some grt shoe shopping and jewelery shopping there. If you do go there try August for brunch. VERY good food but not grt for dinner, best for brunch/lunch. Also Blue Ribbon, the rest and the bakery..also good.
I would pass on Magnolias, the icing is very rich and its just not worth the wait, if you need to stand there for 20min its a waste of time. Tisserie has fantastic pastries they are at Union Square, there is also another bakery (cant remember the name) a block away from Magnolias that I think is better IMO.
If your in soho there is a grt place for coffee called Aroma on Houston, grt coffee and you should try their alfajores...YUM!
One last thing, Pegu Club also on Houston has grt drinks, nice place to go out at night before a club or dinner...whatever. you can dress up for this place, its sexy.
HAVE FUN! I love my city =) hope you do tooooooo!