In my area, we have a michael’s and a joanns that are about equal when it comes to selection…that said–in a nearby city (about 10 miles away) there is a “super joanns” that has a huge selection of everything! I much prefer a lys but if I had to choose…Joann’s it’d be.
ditto!! but if not, then go to Joanns!!! 
in different areas of the country, Both Joanns and Michaels have vastly different selections in stores. Here, they both have about the same stuff. I shop at Michaels to use my employee discount when I want to use a cheap yarn.