The reason I love Harry/Ginny is the exact reason many people don't. It's subtle, it's not the central plot of a story which ISN'T a romance novel. It serves its purpose and doesn't get in the way, but is always there beneath the surface to support the hero on his journey. For me, it is the most fitting relationship for Harry (and I'm not even talking about Ginny as a person here, though I think she is also the most fitting, but the way the relationship is written). It doesn't need to be the centre of things to be great... it needs to be real. H/G, IMO, is real.