Auberge is a great way to meet some princesses, so that's a great way of doing it - you probably already know but you get 3 princesses, one prince, and two cinderella mice normally. We did it once and met Aurora and Prince Philip, CInderella (she was the best Cinders we've met!) and Belle. Also look for other timetabled meet and greets during your visit - for example, this March there ere timetables M&G for Merida and Tiana & Naveen. So if you're not keen on the surprise element, spend your time queuing for those instead.
The Pavillion is really annoying as far as I'm concerned. It IS a long wait. Why they don't install some simple benches to perch on is beyond me! lol But we've also had some lovely experiences. We've met Aurora, Merida, Ariel, Cinderella, and Rapunzel (had a tip off on twitter that she was there almost all the time this March - DD coloured and brought a special picture for her so the CM 'helped' to make sure she could hand over the picture directly!). The best was the one year when I was heavily pregnant, had the special access pass for the day, and were able to book a slot with a 5 minute wait at the exit. DD complained though because she wanted to see the Magic Mirror half way through the queue line so we HAD to go back in there again this year! lol
There are sometimes other random meet and greets that occur - for example, this March (and I think this is happening a lot due to the refurbs this year) we saw some random M&Gs completely by chance in the Studios - Belle in her 'day' outfit, Ariel & Prince Eric together (!), and Snow White - who we'd been trying to meet for ages so we just queued for her.
HTH
C x