These are the projects done professionally for companies or organizations, they are generally based on industry requirements and inputs thereby:
At MAQ Software ( My first Job) I had a dual profile of software tester and a UI designer. Within Software Testing I was involved in various projects related to Microsoft Genuine products. Most of the tasks like writing Test Cases, Test Plans or Executing Tests was learnt on the Job. The unique skills needed by software testers to identify the right test scenarios, find bugs, document them and communicate them rightly to the developers were one of the greater learnings. I was involved in Unit, End to end, Regression and sometimes Security testing.
Most of the testing was based on web based or internet connected client based appplications. One of my projects for security testing of browser toolbars was among the challenging projects where I learnt more about the internals of web browsers and operating systems. From a design perspective this was a great learning via reverse engineering of operating systems and web browsers.