Starting off strong...the Tyrells. I find that this is a house that tends to be very overrated and often overlooked. Let's be honest here, Lady Olenna knows what's what. If she wasn't like, 100 years old, she could totally be running shit. Of course, the ever-so-adorable Margaery is a lot more cunning than people give her credit for. After all, she's taken on Cersei and in my opinion, Margaery is taking this one. Though I guess that's not really saying much. Cersei is mostly just a mess. But nonetheless, you've got to give it to the 16 year old who can take her down. And all while looking incredible.
If Westeros had music festivals, you KNOW Margaery would be there, front and center rocking her floral crown, and charming the crowds. Actually, that might be more Loras' scene. Either way, music festivals would surely be a Tyrell haven. They allow you to interact with all kinds of new and exciting people, find friends and allies, and get in touch with nature, if only by sleeping outside and not showering for days at a time.
Margaery is not known to be afraid of showing a little skin. With the summer heat coming into full swing, she would surely be the festival scene queen. And really, what's a queen without her crown?