I really enjoyed Wonder Woman: The Circle. It conveys all the best qualities of Wonder Woman. She sees all the details of a situation without losing sight of the big picture: a great strategic and diplomatic mind, strong, fierce and compassionate.
Mercedes Lackey wrote a great introduction for this volume, but I would hold off reading it until after you've read the book so you can form your own opinions unbiased. However, if you need to be sold on reading it, then by all means, read the introduction first.
The Circle is the collection of issues #14-19 which covers two main stories, the first including a version of her origin story in #14-17 and the second in #18-19. I love the art by Terry and Rachel Dodson in issues #14-17; I think they've really captured the essence of Wonder Woman.
My Dad saw the cover, flipped through a few pages, and said, "Wonder Woman looks mean."
"What, do you expect her to be all doe-eyed in the middle of battle?"
She does look fierce when she's fighting, but that's what makes her an Amazon. She looks like someone not to be trifled with. And yet she has humor, affection, and great wisdom. She is without question heroic.
Also, bonus: no Steve Trevor.
There were a couple of references I didn't get, nothing crucial to these stories, but I'm trying to track down the earlier issues before reading ahead.