Nice list. Also, a clipboard recorder is a pretty common task, particularly when getting to grips with threading.

Not only software, but individual components can be cool to make.
Stuff like:
- An advanced tab control, with drag/drop to reorder the tabs, a cross button, and a button to add a new tab. (Like in most popular web browsers)
- Syntax highlighting in a rich text box control
- Implementing intelli-sense like features (like in VS)
- A find/replace dialog box can be a neat little project, and it's very re-usable~ Also stuff like regex searches, to make searching much more interesting
Another common software project is data scraping~ there are also a lot of freelance jobs which require data scraping apps, so it could be pretty beneficial to read up on this stuff. Particularly more advanced data scraping, in which you have to provide network credentials to log in and access data from within an account.