I started off as a B.S in CS and now I am a B.S. in Mathematics. I do not really have any experience with the resumes or the work world however I would say knowing math is very useful. I would further emphasize the fact that the gaming industry appears to be moving towards networked gaming or massively multiply gaming with trends in free-worlds and dynamic playing. A minor will not give you the depth to model much of that but it will give you the ability to understand and appreciate it.
Since it will cover calculus it will give you understanding of the mathematical tools necessary for optimizing situations. Since the math will be available to for the methods you wish to employ it will mainly be up to deciphering a way of implementing it both correctly and optimally.
Almost all games are pushing AI development and implementation into different facets, whether it is NPC or meta-level world and ontology generation and management. At this point computational power is prohibitive for many of the most powerful tools but with a planned career this does not matter so much.
The minor will probably require a statistics class and your knowledge of algorithms will most likely be sufficient. I am not sure if any current games include such computationally expensive simulation methods especially on massively multiplayer scales but I can foresee the use of Monte-Carlo methods.
In any case, perhaps it is merely my bias but I would get an M.S. as well. I imagine that would make you more marketable for a longer time and give you more freedom. Otherwise I imagine you will be just coding, and that seems liable to be outsourced.
Another option for a minor would be psychology, sociology or economics. The first two I imagine would emphasize your ability to appeal to and understand gamers while the third would give you a grasp of markets (many game developers struggle with generating realistic markets for trade) and present the possibility of the managerial route. I imagine a company could at some point (after showing promise) offer to pay for an MBA. I imagine would allow you enjoy both the gaming aspects and the freedom whether you are in a company or decide to manage your own studio and produce games, which increasingly is becoming an option due to digital downloads.
I initially was just going to push math all the way but I imagine the economics minor will give you the most freedom and happiness.
I hope that helps.