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