According to Wiki, Homer Simpson had 188 jobs in the first 400 episodes of the series.
Here is another page with a list of his jobs, including:
Acrobat
Actor
Army private (2 times)
Agent (3 times)
Ambulance driver
Amateur-Division Professional Arm Wrestler
Asking man at products demonstration
Astronaut for NASA
Assassin
Attack-dog trainer for the Pitiless Pup Attack Dog School
Baby Proofer for his own baby proofing company “Wee Care”
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Sailor in the Naval Reserve
Sanitation Commissioner
Security Officer of SpringShield
Sideshow freak
Silhouette Model
Singer
Smuggler
of beer
of prescription drugs
of fruits and vegetables
of Sugar
Snowplow proprietor and driver
Soccer referee
Soldier
Softball Player
Street musician
Superhero
Spokesperson/Walking Billboard
Sprawl-Mart greeter
Talk Show Host
Teacher
Television Producer
Telemarketer
Tomacco Creator/Farmer/Salesman
Tow Truck Driver
Town crier
Traveling salesman of Simpson & Son, Revitalizing Tonic
Trucker
Union leader
Used Car salesman
Voice actor
Webmaster (“The Computer Wore Menace Shoes”)