Southwest has round-trip flights from Chicago (MDW) to Houston, Austin, New Orleans, Atlanta, Tampa, or Baltimore (HOU, AUS, MSY, ATL, TPA, BWI) for $108, NONSTOP. $54 each-way. Flights between October and March. Origin/Destination reversible.
Note: You can save up to an additional $125 if you purchase your Flight+Hotel together as a package on Southwest Vacations and use the 125DOM19 coupon code.