4th gen has too little content compared to other gens. They already lose because of that. 1st gen had shitty music, I won't change my opinion on that. 2nd gen had great, fun and unpretentious music but most of it sound outdated now. So 3rd gen wins, but it's not like they released masterpieces back and forth either. They do have better and less dated songs overall, though.
I'm curious as to what you mean by 4th gen has too little content compared to other gens?