Other than C++ and Java, what other programming languages should a CS major learn, if any?

Different programming languages each have a different strength. The computer language that you should learn depends on what kind of programming you want to do. For videogame development (especially consoles) you want to learn a low-level language Like C because the lack of abstraction makes the program run faster on leaner hardware. For something like webapps or browser programming you would want to learn something that runs on a framework with more built-in tools like Ruby or C#.

One of the important concepts is how much work is being done by the processor vs. by the programmer. Some languages require very exact and careful programming but work very fast, others allow you to write very quick programs but the built-in tools can slow things down. Its like driving a motorcycle vs driving an RV, the more tools you bring along, the more resources you have to spend to get where you are going.