It will ultimately depend on what you want to do with your degree(s). Typically in law your second degree is oversighted anyway as they are looking for your particular talents as a law student and potential lawyer. At my firm, there's a mixture of Journalism/Law, Med Sci/Lawrence, Arts/Law and Comm/Law and it's similar in other firms. Arguably Commerce/Law is most employable, but that would be due to the fact that Commerce is a good generalist degree that offers qualification in an industry with more jobs than perhaps Media. In any event, Media would certainly be a good degree to combine with Law in light the influence technology is now having on law firm practices and in "the age of technology". This article might be of some interest to you:
http://www.theguardian.com/law/2014/nov/26/careers-for-the-21st-century-law-student
Obviously if you wanted to work in the Commerce or Finance industry you should look to doing the Commerce/Law combination.
My biggest regret is doing a Business/Law degree instead of Communications or Arts/Law and probably would have swapped were it not for Economics. Don't do what people think might be more employable since you won't be if you don't even enjoy what you study.