I usually only share my fiction with friends, so I don't have experience with outside feedback yet.
With that said: My brain tends to default to "Well, of course they're going to say something nice. It's like an obligatory friendship reaction!" The only response that gets past "pfft, you're just saying that. I know I'm unworthy," is when they engage with the story context or react on a philosophical level.
Even if they end up not talking about the story itself but some topic that the characters brought to mind, the fact that their reaction started a conversation is what matters. It's a special feeling.
@Tamachii -- Fan-response art of any kind would be so much fun!