One thing that I have noticed that makes hard drives last longer(particular WD Raptor drives lol) was to stick a fan in front/near them. Otherwise, it don't really matter which one you buy from a reliability stand point.
i am looking for a hard drive that will not fail on me if i use the pc 24 x 7, i just want a reliable drive that will stand the test of time. So which one will be more reliable the WD Black or the WD Red??