This is a great question. It's been popping back into my head since you asked, and it's spawned a really interesting thread.
I humbly submit that, broadly speaking, the feedback you get from these different groups is all useful, but differently useful, like Valerie said. So perhaps it doesn't make sense to rank them so much as it does to incorporate them all into their own happy little niches. (Note to self: Happy Little Niches, narrative format that involves a bunch of small, extremely specific, pop out scenes that are seemingly unrelated to each other and the primary storyline but then come together in an amazingly last-scene-of-Harold sort of way.) Each of these groups has a different idea of what constitutes a "good" show.
The Audience (Heart): I love this concept of Audience with a capital A. And Chuy is right. Entertaining the Audience is our job. For the most part, the Audience doesn't care if you're doing "good improv." Of course "good improv" is more likely to create a better experience for the Audience, but they don't know that. They're happy if you're making them laugh/cry/think. If they're having fun/feeling something/engaged, you're doing some things right. I like to think of the Audience as a good judge of your show's "heart" and ability to welcome an outsider into that heart. (I recognize and embrace that that's super cheesy sounding.) A show that has fantastic technique but no heart will not engage an audience, but audiences love to watch people just having fun.
The Peers (Head): (If you are an improvisor, but you happen to be sitting in the audience, you are a peer.) Unlike the Audience, your peers tend to know what you "should" be doing. They'll recognize when you dropped an offer or walked through a table or failed to react to something major. Most importantly, they'll notice patterns that you tend to get stuck in and ways in which you tend to unconsciously limit yourself. Your peers can tell you ways in which you can discover and communicate your heart better.
The Self (Ego): You are the only one who knows if you did your best work. If you pushed yourself. If you took risks. If you tried new things. If you accepted the moment and told your inner critic to fuck off. If you connected to your fellow players.
Just because one of these groups says you had a good show doesn't mean there's no room for improvement. Just because one of them says there was a problem with the show doesn't mean it was a bad show. I've beat the crap out of myself after shows that audiences loved. What's the point of that? Might as well take the good with the bad and recognize that, even though you might be right to criticize yourself, tomorrow you'll do better, and for today, you made the audience laugh, and that's not nothing.
I'm Maitland Lederer, and I approve this message.