I did maths Pure and Decision (Decision is heavy on expected values, predictions etc, links well to computing as its very logical)
Economics
Computer Science (it actaully was decent then, learning Cobol, understanding all hardware etc)
Looking back now, Economics and Decision maths have the most relevance to the real world.
Computer science dates fairly heavily unless you go specifically into hardware/software and then I doubt much of the history counts for much.
Economics gives a nice feel for and general understanding of the macro business environment imo. When you start going more specialist (eg degree) its less relevant for day to day in the real world. Probably like most "sciences" (Chem, Maths, Biology etc) there is a point where the real day to day benefits of an understanding will bear no relevance unless your career leads you into that field.