I assume that you're thinking of places within walking distance of the DePaul campus since lunch, like life, is short.
I'd second the recommendation of the Bourgeois Pig, but add the caveat that it can get busy and crowded there in the warmer months.
Around the corner on Lincoln is Nan's Chinese (2360 N. Lincoln) , and my favorite Syrian place has been replaced by Simply It (2269 N. Lincoln), the confusingly named Vietnamese place. I've never tried either one, though.
If you're a fast walker, you could go up to Diversey and try out Penny's or Satay.
My physical therapists at DePaul all ate at Pockets (they also deliver), for what that's worth -- I've never actually eaten there, but a group of very athletic people seemed to feel that it was the healthiest option in the neighborhood.
Calliope Cafe has closed.