I can tell you the quality shows I do that have proven to be excellent over the years....
May 7 & 8, Mothers Day weekend, "Art In Bloom", Downtown on Main Street, in Medford
http://www.art-in-bloom.com/August, "River Art Walk" in Shady Cove
http://www.upperrogue.org/riverwalk/index.htmAugust/September, tba, "Jacksonville Celebrates the Arts", in Jacksonville
http://www.oregonfestivals.org/node/2454November, "Nazarene Holiday Show", on McAndrews Road, in Medford
Some of these are not easy to get into and may have a waiting list but they are the best in the area. I would not consider a show that didn't have a jury or high standards.