Needing some short fiction titles, please

One of the other hats that I wear besides blogging and making an online fool out of myself is that of a teacher at a residential treatment center. Although my areas of public school certification are in the social studies, here I have to teach all subjects. While Language Arts is not a problem in general (my mother has taught English at both the middle school and high school levels for the past 37 years), trying to remember specific titles that I could use that a) would be enjoyable and b) I could use to assess knowledge and understanding of themes can be a problem.

So here's a bit of an open forum for suggestions. Since I teach students whose reading levels range from a 1st grade capacity (I'm having to teach two teen boys how to read) to college-level, it is challenging to come up with interesting stories that I can use for each subgroup. While I'm currently using Lois Lowery's excellent The Giver with my female students, I'm finding myself needing shorter stories that can engage them without being overly this or that. So, what do you suggest for me to buy over the next month or so (if said stories aren't public domain and available online)?