Refined Knits contains some lovely patterns, including this cabled beauty.
This is not the kind of sweater you make because it would be a useful addition to your wardrobe or because it would be flattering, but because it would be a satisfyingly epic project and would show off your knitting skills. I’m not sure I actually like it as a fabric, even (all that reverse stockinette!), but it is definitely on my list.
Here’s another lovely project from the book, this one with Japanese lace. Again, probably not your wear-everywhere sweater, but I’ll probably make this one.