You don't mention if time of year is important, so off the top of my head:
Empty Spools
http://www.emptyspoolsseminars.com/
Quilt Museum Workshops - Paducah
http://www.quiltmuseum.org/adult-workshops.html
Quilting by the Lake
http://www.quiltingbythelake.com/
Quilt Festival (Houston and other cities)
http://www.quilts.com/home/index.php
They also run a few Quilt Camps a year.
Ricky Tims runs his LaVeta retreats - I've heard rave reviews about that.
https://www.rickytims.com/retreats/retreat-info
AQS Paducah Show - class list not yet available (or any of their other shows)
http://aqsshows.com/AQSPaducah/
That's it for now. Oven timer is dinging.