I really like M57 at fairly low magnification in my 13". There is something cool about looking at a field of lots of stars, and then seeing that one of them isn't a star, but a tiny and very well defined circle. (It beats finding most of the other planetaries which at low magnification just look like one of the stars didn't get into focus. Though that's kind of cool, too, like Mel in Deconstructing Harry. :-) )

At higher magnification, I've seen hints of faint color and of structure in the ring (could of course be my brain playing a trick on me). Really nice, too.