Some of the contradictory ones are the most interesting. Such as the contradictory studies with coffee consumption, which eventually pointed to filtered vs. unfiltered coffee giving different results (so studies done on populations drinking mainly filtered coffee differed to populations drinking mainly unfiltered). I also find it is worth looking closer. The headlines in the papers might be contradictory, but a closer look indicates the studies are actually measuring different things and they are not contradictory at all, perhaps even reinforcing.

Coffee is a strange one though. I think I've only seen 'coffee is good' in recent years, but I'm wary because I don't expect 'coffee is bad' studies to get the same sort of publicity.