Just as in fashion, jewelry trends (unique shapes! colored stones! new metals!) come and go. For an engagement ring you'll love as much 10 years from now as you do today, opt for a traditional diamond cut and fuss-free design that will never go out of style.

Platinum engagement ring with emerald-cut diamond center stone and tapered baguette diamonds, $1,800 (without center stone), Blue Nile

See more emerald-cut engagement rings. Photo: Courtesy of Blue Nile