Here's a beautiful strapless long formal dress that is as classy as it is alluring. From Amelia Couture, this long designer dress hugs the curves from the cowl neckline to the floor, while side ruching creates a fitted look. The elegant evening gown includes an eye-catching side drape that flows behind the hip-hugging long skirt as it opens in a side slit before reaching the floor. So elegant for prom, military balls, and other formal events, this strapless long formal prom dress is surprisingly affordable, at under $200.