Well, welcome to the neighborhood! I am only about 12 miles from the Ben Franklin where you are starting! Ben Franklin has a fairly conservative selection compared to our dedicated quilt shops...and there are LOTS of great ones!
Here are my suggestions:
If you will be traveling further north, there is Cotton Pickins in Stanwood, WA which is a gorgeous shop, one of the prettiest in the state. Aunt Mary's Quilt Shop in Smokey Point is also a nice shop. That trip is about a half hour, or 35 minutes from Monroe.
http://www.auntmarysquiltshop.com
If you are traveling south, towards the Seattle area, then a MUST stop is Quiltworks Northwest in Bellevue, WA which is on the East side of Lake Washington. It is BIG, with LOTS of fabric, beads, books.
http://www.quiltworksnw.com
Bayside Quilting is a very fun shop, as someone mentioned already. It is in Olympia however, which is going to be well over an hour from Monroe but worth the trip if you love quilt shops.
http://www.baysidequilting.com
If you are making the trip to Olympia, you must plan to travel through Puyallup, WA, to my very favorite quilt shop: The Quilt Barn. If it happens to be the month of your birthday, take your driver's license and get 25% off your fabric purchase. I don't believe you'll find a larger selection of batiks in the state (and lots of other fabrics as well.)
http://www.quiltbarn.com
Also in that general area is Shibori Dragon, great selection of asian fabrics and wonderful patterns, and a huge selection of gorgeous threads.
http://www.shiboridragon.com/
If you are traveling on the ferries, crossing over to the kitsap peninsula, then the Kingston Quilt Shop in Kingston is wonderful, and Heirloom Quilts in Poulsbo is another MUST stop. In Silverdale there is Material Girls, which I also like.
kingstonquiltshop.com
http://www.materialgirlsquiltshop.com
http://www.heirloomquiltsandfabric.com
Hope you have a great time!