Most of my maternity wardrobe comes from Motherhood or Target, but I haven't loved either one.
The Target stuff looks better on me and has a more comfortable waist style, but it doesn't last well--it gets me through 1-2 pregnancies depending how much I wear it. The Motherhood stuff lasts, but I've been very disappointed in their waists and overall clothing style. (It's also more $ than the Target clothes.) I tried the secret fit belly for one of the few pairs of shorts I bought this time (my 3rd pregnancy, but I didn't have shorts yet), and I hated it. It doesn't stay up on me, so I had to fold it over and then got the band around the middle that the secret fit supposedly eliminates. In part where I'd recommend shopping depends on how much you plan to wear things. If it's just for one pregnancy, I'd go with Target.