How do I find sellers with the most items on my Wanted List?

To view the stores that have the most items in your Wanted List, visit My Wanted List and click the "By Shop" tab, then change the "Sort By" drop down list to "Lots Unique". The stores that have items on your wanted list will be sorted by who has the most on top.
Here's a quick user-made tutorial on YouTube that we found helpful:
An alternative option is to use software that some of our users have made such as BrickStoreBrickficiency or BrickWizard, but we cannot provide support on how those work. These software programs can help you keep track of your lists if you need to break your orders up between multiple stores.