I almost always show my writing to my husband first just because I know he won't sugar-coat anything. He's not afraid to tell me what sucks, what doesn't work for him, where I'm being lazy and not writing at my best, or where my MC is being too passive. He's also not afraid to tell me what he likes.
I can always go to him for brainstorming. And he's not afraid to tell me if something's really stupid. Though there've been time when he'll later tell me this really cool idea and I'll have to remind him that he thought it was stupid when I first mentioned it. Of course, he doesn't think it's stupid now.