Obie's is interesting but too crowded to be able to look at much. It's a place to go when you have plenty of time. I would go to Weaver's in Lititz or Burkholder's in Denver. They aren't too far apart and both are great. I was just in Lancaster last month for a day and a half of fabric shopping and was very disappointed with Sauder's. Didn't think it had nearly as much fabric as it used to.
Have fun - it's a great area!