Any languages chosen should be practical, real-world tools. This throws out BASIC, Pascal, and Fortran. No "teaching-only" languages please.
I would teach the first half of the class in C. "Silly mistakes" is the name of the game here. You need to learn compiling, linking, array bounds, file I/O, how to make strings. What C teaches you is that if you are willing to stack bytes one at a time, you can eventually build anything. This is my bone to throw to the architecture crowd. And when you link to graphics libraries, you can do some visualization. This will be the payoff for suffering through array hell.
The second half I would teach PHP and web protocols. Get, post, making forms and passing variables. Urlencode and decode. Database connections and some basic SQL. I've seen this stuff taught in 3 weeks, and it's extremely practical. Making selectboxes. If you can make a selectbox, you're a fucking pro.
This would cover a whole class imo. Installing linux and using apps can be another class. And it would be a good class because linux is extremely non-obvious yet quite pleasant when it's working.