I have dabbled a bit in German soaps over the years...
I watched GZSZ just for a brief period a few years back, I only followed the Lenny and Carsten storyline.
I used to watch AWZ a few years ago, mainly to follow Deniz/Roman, but I really liked the whole show. Then I eventually stopped following it, because my German is abysmal and I couldn't follow without subtitles.
I also used to watch Verbotene Liebe, which has ended.
My sister has been watching religiously Sturm der Liebe (which unlike the other soaps is aired in Italy, dubbed) for 10 years, so I'm familiar with it..but I can't say I am a fan.