Here is the full list of all 25 Totally Reliable Delivery Service achievements.
Complete 100 different deliveries.
Complete 50 different deliveries.
Pass gas in a biplane.
Visit Gasa Research Facility.
Return the satellite to GASA.
Bring foam hand to Booster Club Arena.
Unlock the rocket booster.
Lose pants in tornado at Happy Clam Resort.
Bring banana to room 5 at Banana Motel.
Visit Keister Island.
Bring the luchador mask to wrestling ring.
Put treasure chest on sloop.
Find the tiny island.
Unlock the pickup truck.
Bring the conch shell to top of mountain.
Bring grill to Dad Statue in Golden Ruins.
Find the big secret bear.
Unlock the helicopter.
Visit Happy Clam Resort.
Complete 10 different deliveries.
Unlock the buggy.
Unlock the mule.
Remain airborne for 10 seconds.
Complete first delivery.
Change your clothes.