I like the Meereen plot because it reminds me a lot of my liberal friends' ideals. It's a typical white fantasy of somebody from a "more civilised" country going to intervene with a bunch of brown people's long established customs to make them more politically correct and supposedly lift them up.
Of course it's a terrible idea, as slavery was the one thing keeping Slaver's Bay together and stopping everybody from eating each other. She completely fucks up the established order to the point that the place is now much more of a mess than ever before. Dany is going to go to Westeros having experimented on brown people before she can "move up" to rule white people, where her consequences will actually count to her. She really is quite a nasty character, and I see her as more of a villain. I think she's in for a nasty shock when the people of Westeros see her as a horrifying terror threat and not their messiah.
Meereen was a great, hugely interesting idea.... botched by its execution. If it was cut down to 5 chapters that were spread out throughout the book, nobody would be complaining.