It depends on what you are more interested in.
For general purpose software, C# or Java would be the best choice. Java tends to lean towards server applications and C# more client applications. They both have very similar abilities (e.g. they both use garbage collection). You will find the most available software jobs in these two languages.
I would avoid Programming in HTML. While you can program in HTML, HTML was designed for document markup, not UI software.
C would be most useful if you are interested in OS level programming and constructs. It's a somewhat tougher row to hoe, as C does not come "out of the box" with the same extensive libraries that Java and C# do. However, understanding C is a necessity to understand OS kernels such as Windows and Linux.
Programming with Microcontrollers would be best suited for learning about embedded work (i.e. controlling physical devices). If you want to run the servo motors to make your robot move, this is the place.
A lot of jobs involve web design and programming, so some understanding of HTML is necessary. However, there are numerous ways to program web sites. Not only is there scripting the browser itself (via things like JavaScript and HTML programming constructs), there is software running on the server end, determining just what HTML to send to the client.
Overall, the best thing to do is look at what types of programming jobs are available in your area and see just what skills are in demand.