Hint: Beach Ball (Vice City)
On the Leaf Links golf course there is a sand pit with a beach ball in it. To get there go to the spot where you kill the golf player on the platform. Then walk diagonaly right, away from the platform, until you see the two sand pits. The beach ball will be in the bigger pit. If you shoot it it pops, and might not come back.

Hint: "Easter Egg" Easter Egg (Vice City)
Head to the 8-10 VCN Building (the news building) on the west island of Vice City. The news building is by the northern bridge entrance on the west island. You can enter the door of the news building and head up to the roof.

Along with the news chopper, there's an easter egg you can get to. There's another buiding close by, but on an angle with the window closest to the edge of the heliport. Make a sprinting jump through the window and you should see an empty room with an easter egg in the middle.
Submitted by Demion
Hint: Free Car Repairs
Drive a damaged vehicle into a garage that you own, get out of the car, and leave the garage. Wait for the door to close and then go back inside the garage--the car will be in perfect condition.
Submitted by Briblade
Hint: Stop tanks in their tracks
On The Front of each tank is a small opening. You can use a sniper rifle to snipe the heads of the enemy soldiers driving the tank.
Submitted by Kyle
Hint: Scarface Easter Egg
In Vice City, there's a Scarface easter egg in the form of a bloody bathroom and a chainsaw weapon.

Go to the Pay N' Spray at Ocean beach, then go south and take the first left. On your left, you'll see a two story apartment with two sets of stairs on the second floor.

Head up the stairs to the right and you'll see a black doorway. Check out the bathroom in apartment 3c and compare it to the movie.

Hint: UZI Ammo (Vice City)
Here's an ammo cheat for Vice City. Go to the Biker Bar (where you can do missions). Put your back to the front of it and run to your right and around the street corner. Then look to your left. You'll see a staircase leading up to a rooftop. There is Uzi 9mm ammo underneath it. There is also a shack that you can buy on the top of the roof. You can travel between the save point at the shack and the ammo as many times as you like, as right after you save, there is more ammo there again.