I've talked about minimalism in the past, but here's a great example of using just enough minimalism to make a decent cover.
Why does this work? Well, OMD's Junk Culture has a wonderful cover. It's white text on black, with bright, vivid flowers dropped in around it after being run through a blurring visual effect. Are they glowing out of tune or shimmering or just too far away? What is with the blurry flowers, anyway? That's what makes this a good cover. The elements are simple, but never simplistic. This is supposed to signal that we have art, and a bit of romance on board, and that's all well and good.
What works is that the cover does exactly what it's supposed to do--it provides enough of an indication as to what you're getting while leaving what's inside a mystery.
Was there ever a more disappointing record label than A&M by the way? How many artists did they drop? Tons of them. I suppose every label did that, but A&M always dropped artists that I liked.