Let's discuss the different types of maxi that can flatter each body types.
If you are busty, a V-neck maxi with an empire waist, is a great choice. You can show off the girls a bit, keeping it sexy and classy, and the empire waist with a flowing A-line shape will keep it from beign over the top. This one is from www.zoebrianne.com, and it goes for $85.
If you are pear shaped the most important thing is to find a maxi that can accentuate your small waist and that won't hug the hips too much. Anything belted or cinched at the waist is going to look awesome. The belted one below is from Dillards by Gianni Bini and goes for $71. Prints will also play to your favor hiding any imperfections. The striped maxi is by Chelsea and Violet, which can be found at Dillards for about $70.
Lastly, for the athletic build or boyish figure, fitted maxis will flatter you well. A maxi with extra fabric can look well on a boyish figure like one with ruffles or a tiered style. But, be careful because too much fabric can overwhelm a boyfish figure and it will look like you are swimming in your dress.
Target sells a halter style maxi that is fitted through the waist and then flares out which is super cute at $28. Jessica Simpson makes a watercolored maxi great for the atheltic build also. Its not too much fabric but it is flowy, and the empire waist of the dress gives an added push to the girls up top. It runs for about $70.
Also at Dillards Gianni Bini sells a very nice printed A-line racerback style maxi great for all body shapes which runs for about $119. It is kind of fitted, which works for the boyfish figure, it's not too tight and it is printed with a small waist which works well for the pear shaped and it is low cut but not plunging for the busty gals. It is also textured so it hides any imperfections.
No matter what body type you have, there is a maxi waiting for you. Be sure to check out stores like TJMaxx and Marshalls for discounted dresses. Also, try stores like Clothes Mentor (http://www.clothesmentor.com/). It is a fabulous spot for checking out second-hand, name brand maxis(and other apparell) at an extremely discounted price. I actually just gave a box of items to Clothes Mentor and I can't wait to use my store credit and shop the racks.
Whatever you do, when you find the perfect maxi for you, you will understand why I think they are so amazing and you will have a one item casually charming outfit on your hands! Happy shopping!