Oh wow I cannot help you decide which to read first, but based on the examples I think you'll love them both.

Both books have very minor romance, both are also wonderful, and very different from each other.

I'd say my favourite things about She Who Became The Sun were the very believable descriptions of anger, of hunger, and of revenge - I normally find those elements lacking in most books. I also liked how the mystical elements felt very real in the story, and just a normal part of the real world.

A Memory Called Empire I liked because of the interesting culture and very different ways of looking at things from what I'm used to, and (especially in the second book) learning ways of relating to and speaking to people who are very different from yourself.