If you want to go to American, go work for Piedmont, PSA, or Envoy.

If you want to fly for Delta, go to Endeavor.

If you want to fly for United, go to CommutAir, ExpressJet, or maybe SlyWest?

While pilots from every regional get hired all over the place, look at the regionals who either have or are developing partnerships for moving their pilots up to mainline.