Anyone who tries to assert that nothing happens in the series is completely blind to what the point of certain arcs were. You may not like what happened, but that's something entirely different. For example, one of the most often exemplified stories were 'nothing happened' is Dany's. Well, here is what happened:
Dany, upon realizing that being a queen required more than burning all the badguys and leaving the citizens there to behave, tried her hand at ruling Meereen as a test drive before her march to Westeros. In during her reign, she realizes that her dragons are dangerous beasts and ties them up. She tries to impose her rule, but due to the strife she has caused in the other cities as well as the different cultural norms, she struggles with keeping her city under control. To do this, she concedes to marrying one of the noblemen. Quentyn eventually comes and she must reject him, leading him to his little journey into the dragons lair. Eventually, Drogo comes back and takes her away.
So what has her storyline accomplished:
1. It developed her character. She thought she would just return to Westeros and be the rightful, benevolent ruler. By the end, this perception is shattered. She cannot build, only destroy. Furthermore, by trying, she has completely failed all the followers she swore to help. Who knows if she even wants to come to Westeros anymore.
2. She has lost 2 of her dragons, and all her followers are left in Meereen while she is all the way in the Dothraki Sea. She is starting over, in many ways
3. She is now officially married, so it's not like she can take another husband in Westeros, or at least not without breaking lots of rules, which has it's own consequences.
4. Because he rejected Quentyn and he died as a guest of hers, there is no way Dorne will ally with her if she does come to westeros. The lost a major ally there.
5. Due to the prophecy, she might be able to bear children again.
"Nothing happened." Bullshit.