The Last Of Us for PlayStation 3 features a secret gold trophy entitled "That's All I Got". In order get this trophy, you must listen to (a.k.a. suffer through) all of Ellie's jokes throughout the journey. Keep an eye out for Ellie's jokes after she finds the joke book in Pittsburgh. This guide will let you know exactly when to expect some humor coming your way so you can snag this gold trophy.
The first joke will happen after you cross through the hunter's camp, after Ellie tells you that you can cross the bus. Wait for her to discover the joke book and start reading from it.
The second joke is also in Pittsburgh, after you clear out the bookstore. Wander around on the second floor until Ellie pulls out the joke book and starts reading.
When Ellie and Joel are back outside, look for a dead end. There will be a picture of a model on a nearby building, and Ellie will comment on it. Wait here until Ellie starts reading from the joke book again.
The last joke in Pittsburgh is inside the hotel. There is a point where Joel needs to find a ladder. Use the ladder to find the safe combination on the blocked landing on the second floor. Return to the first floor and open the safe. After this, run back to Ellie and wait for her to pull out the book and tell you a joke.
The last joke is found in the next chapter, when Joel and Ellie are in the suburbs. This joke actually has multiple conversations that must be triggered in order for the last joke to appear and the trophy to pop.