Supershuttle operates a van service to both Dallas and Fort Worth. Best deal to Fort Worth is the Airporter Bus Service. Buses depart from the airport every 30 minutes. There are no counters in the terminals. Go to street level and take a shuttle bus to the rental car lot.
Fares increase with the number of passengers.
Private bus companies such as Dash and Airporter stop at large downtown hotels and other destinations. Use the courtesy phone in the baggage claim area to book your trip and they'll arrive in 15 minutes. There are other van services to all areas of the Los Angeles area. Inquire at the ground transportation desk. There are special taxis for short rides in the vicinity of the airport.