Are you willing to travel to Stockholm, Wisconsin? The Stockholm Pie Company has the best pies in the Midwest. In the metro area, Birchwood's key lime pie is awesome, and their baked fruit pies are great if you don't mind a tough (and tasty) crust, but you'd have to call ahead to order a whole pie. Seward Co-op has a very good key lime pie, too, and very nice two-crust pies (when available - call to check). Otherwise, Jerabek's or Key's pies are pretty good.
+1 on that HeavyTable article:
3311 E 25th St, Minneapolis, MN 55406
My go-to has always been Turtle Bread if I'm feeding a large crowd, or key lime pie at The Wedge if the group is smaller.
However, there is some recent side-by-side pie tasting chronicled here:
And I have to say that I agree with them that Betty's Pies does not come anywhere close to living up to its reputation.
700 Wildwood Rd, Saint Paul, MN