As promised, I have compiled and am sending back all the great responses from our generous members. Thank you for your help!
Various websites & Books
The SHRM website has quite a few cases and teaching modules. Many are well-suited for undergraduates. I've used quite a few of the cases in my class. The cases are free to educators. http://www.shrm.org/Education/hreducation/Pages/cases.aspx
In addition, the Stanford Leadership website also has some great videos and exercises that cover all aspects of leadership, and a few HR related topics. Also free to educators.
http://www.leadershipinfocus.net/2-0/index.cfm?Event=location.index&CFID=163360&CFTOKEN=d372a0f738e0d4e-CF589B81-D28A-849E-FC60679530EA79A3
You can find cases for UG students on ECCH.com
Book: Human Resource Management Applications: case, exercises, incidents, and skill builders by Nkomo, Fottler, McAfee (7th edition).
This article has some interesting cases: https://journals.troy.edu/index.php/JHRE/article/view/17
Another good resource is: http://www.amazon.com/Human-Resource-Management-Applications-Exercises/dp/0538468076
Journal of Management Education has several articles with exercises that can help you.
I recommend John Bernardin's Textbook: HRM: An Experiential Approach. I've used it for years and the exercises/cases are very realistic and, I believe, based on John's and other's consulting.
James Michaels
Take a look at James Michaels (A) and (B)
http://www.tandfonline.com/doi/abs/10.1080/15416518.2012.666949#preview
There's a teaching note as well (http://www.tandfonline.com/doi/abs/10.1080/15416518.2012.666950#.Unp3V5Ha2Es). I've used it in my undergrad HRM course with great success!
SG Cowan
I have had great success with the HBS case – SG Cowan. I use it after recruiting, testing, selecting and interviewing as it involves elements of all of these. I ask the students to analyze the four candidates in the case and decide which two the firm should hire. In doing so, they have to consider the company's stated goals, the implied and stated personality, knowledge, and skills needs of the company as well as the information about the candidates. We spend about 80 minutes discussing the case, analyzing the recruiting and selection process of the company and the pros and cons of each candidate. We end with the poll on who should be hired and the (supplied in the teaching note) info on who would be hired. This is not only a good case for the topic, but also gives a lot of opportunity to teach students about how to analyze a case.
I now use four cases of the "briefcases" that Harvard offers in lieu of a term group project in my OB classes and full length cases in my OB, HR, teams, and leadership classes. I find the students enjoy them and learn quite a bit from them. Another advantage is that these students will be prepared for grad school – business, medicine, law, any that use cases.
SAS
SAS is a classic.
http://www.youtube.com/watch?v=N-ebIGpZIWI
http://www.youtube.com/watch?v=9SCxJTmS1Eo
http://www.cbsnews.com/stories/2003/04/18/60minutes/main550102.shtml
The SAS Corp is one "real life" case I use in my classes a lot! There was a short video clip also about Abercrombie & Fitch (I think the video is titled "The Look" which is very useful. If you monitor some of the popular publications (NYT, Business Week, Fortune, CBS's 60 Minutes, etc.) you will find a lot of cases and most of them taking place on real time! The great thing is that students can update themselves and analyze a real event!
HRM Simulation
Have you tried the HRM Simulation, it's a semester long, and I have used it for 10 years, and my students loved it. Saves you a lot of case grading too! www.interpretive.com