While I am not usually a fan of large chain stores due to quality, one thing that I like to stock up on is swimsuits from H&M. I’m not sure what it is, but they always seem to have the perfect fit and just the right amount of eye catching features that make me go back for more. While they will not last you more than a season, I consider a good fit worth it.
My personal favorite is made mostly out of elastic, making it stretch or shrink to fit your curves in just the right way. At about $30 for the top and bottom, you can get it in all four colorways offered.