The turquoise dress
It's okay. I love the glitters around it. I don't like the colour (I like the white parts though). It doesn't fit Merida much.
The dark green dress
I think it fits Merida a lot. It's very pretty and comfortable for Merida's skills. It looks gorgeous especially in the sunlight.
Her brown dress
This is the one she wore when she was young. It's very pretty and it fits her. She looks really cute when she is wearing it.