The thing is, most people really love Berlin for their party scene, but I'm not a party animal anymore. Even if I was, I wouldn't want to live in a dirty and ugly city with unfriendly people just to go out partying.
Hamburg is also not the prettiest city, but it has it's unique style and charme. From the big cities in Germany, it's my favorite. Munich is pretty nice, but way too expensive, so fuck'em.
Here are some suggestions. I actually was at all mentioned places.
Good big cities: Hamburg and Munich. Dresden and Leipzig are okay, too. I would like to go to Cologne or Dusseldorf, a lot of friends of mine rate them.
Good smaller cities: Heidelberg, Freiburg (because you can hop over to France in no time), Würzburg and Regensburg
Meh: Berlin, Frankfurt, Nuremberg
No-Go-Areas: Mannheim, Ludwigshafen, Chemnitz, Wolfsburg, Hannover
Just my personal opinion. I can see why people love Berlin, but it's just not my cup of tea.