I don't know if this would qualify as curb appeal, since it's in the back yard, but I'll post it anyway.
When My daughter got married a couple of years ago, her husband already lived in this house. As a bachelor he did little more than just cut the grass. DD has always had a way with plants and decided to start with a pond as the focal point. I think she's done a terrific job.
Now they both spend most of their time outdoors, it's such a cozy spot.