Personally I think a cooler temp aeropress is the way to go. Cold brew is a good idea too, but if you are looking for your morning cup of coffee, you might not want cold. You can steal a trick from the beer industry and add some calcium chloride to the coffee. Chloride ions suppress the "harshness" of bitter tastes. Some people add salt to their coffee to get the same effect, but then you get the saltiness in addition to the chloride ions.
Really, I think for the most part, the beans make the biggest difference, so there's only so much you can do. When I end up drinking mass market coffee, I'll sometimes just add cream. There's a reason so many people do.