With a German major.., minors like Philosophy & English could be perfect complements.., You can study the original works of many German philosophers in their original language so that nothing gets lost in translation.., understand them more fully.., an English minor could allow you to brush up on Essay writing.., business writing.., expository writing.., and even creative writing if you'd like.. (I took a creative writing class back in college.., I know it sounds like a BS class.., but don't overlook it.., it will take the power of your writing to a whole new level)
Again.., it all depends on what YOU want to do.., where YOU would like to see yourself years from now.., after you get your Ph.D.., how what you choose to learn now.., will benefit you in the future.. you definitely don't want to burden yourself with a minor because you think it "sounds" good or "looks" good..