It wasn't the one I expected to be my favorite. In fact, I almost didn't buy a Wonder Wrap. The store I bought the first one from only had Mandarin, and it was my least favorite color of the four choices... but I figured that trying different covers was the best way to figure out which one would work best for us, so I added it to our cart. And I am so glad that we did!
I ordered four more this week, since Maggie only fits in two of her diaper covers now (1 Wonder Wrap and 1 Happy Heiny), and just received an email informing me that they were out of the Vanilla and Blackberry, but that they have plenty of Mandarin and Kiwi (of course they do...). So we're going to have three mandarin wraps and two kiwi wraps... and that shows just how well these wraps work. I'm willing to get two colors that I really don't like because I know that they contain blow out diapers really, really well.
My only wish is that they made the diapers in cuter colors (or that I could find a store with "vanilla" in stock!).
The Happy Heiny's Diaper Cover comes in a close second. It would be tied or first if it weren't for the fact that the edges of the diapers has gotten kind of linty and the super-sticky-velcro seems to stick to everything (which is why the edges are linty... the diaper cover sticks to itself in the wash...). But it does a great job of not leaking, just like the Wonder Wrap, so it's definitely a favorite.
I'm not really a Bummi's or a Thirsties fan. We just had a more leaks with those brands (although they have a lot of cute patterns and colors, so I really wanted them to work out!) and Maggie has already, at the ripe old age of 2 and a half months, grown out of the size 1's.
I like the words "one size fits all" at the top of a diaper. With babies that grow this fast, it's a must!