The right course decisions really depend on what you want to do careerwise, and going into first year, I expect this to be very very hazy (if it's not, I would be worried

). To give yourself the best chances, I strongly suggest that you choose courses which are generally applicable, and are difficult to learn outside the context of a structured degree course.
I recommend doing all the CS core courses, and then also doing at least CS honours. As support courses though, try to do as much Maths, App. Maths, Stats as possible. Even throw in some Physics if possible, since appart from the interesting work done in Physics, the constant application of advanced maths tends to have the byproduct of encouraging numerical competentcy.
I
don't recommend doing courses (CS or otherwise) with relatively low "science/theory" content (games design, business computing, etc.),
unless you do them as extra credits. I.e., don't
replace Stats/Math/Physics/App. Maths/etc. II or III with such courses, do them in addition if your are interested in their contents. While any education is good, and the practical content of some of these courses may (dubiously) make you marginally more marketable after your degree, the contents of the less theoretical courses are easy to learn by self study, or can be picked up on the job. You should be optimizing for your career, not your first job.
Some other points for a science oriented degree, is that it makes it much easier to progress if you consider doing doing postgraduate work -- much of the academic CS papers out there are very maths/stats heavy, and being familiar with maths as the basic lingo will go a long way. Also, in industry, if you work with others from non-CS scientific field, mathematical competency is the common medium of expression that will help you communicate with them.
Obviously, if you land up with a job working with non-scientists/non-engineering types, turning business logic into code, the above isn't nearly as necessary, but having it certainly leaves more doors open.
My undegrad (@UCT): CS and Math Major, App. Math to 2nd year, and Stats, CS, App. Math., Psychology, 1st year (wish I did physics instead

). I did a CS Honours afterwards.