I'm with kzoom - if you can get past the fact that it's a Hyundai, the loaded-up Azera is a very nice car. Big, comfy, and if you're driving that far, you'd going to want XM.

Other than that, go with the Avalon hands-down for four adults. If it were just you, I'd say try to grab that Audi, because it's a helluva lot more fun to drive than an Avalon. But for roominess, Avalon is a good call.