Donkey Kong 64
Rainbow Coins
If you haven't noticed already, there are mounds of dirt with the letters "DK" on them hidden around the game. Stand on top of one, and use the charged attack (hold down B). The shockwave from that attack will destroy the mound, and a large rainbow coin will come out. This special item will give 5 Banana Bunch Coins to each of the Kongs. Now you shouldn't have to worry about money once you start collecting them!
Credit Goes To: MetroidMoo (metroidmoo@earthlink.net) via N64cc
 Rainbow Coins
 Get the Nintendo
 Coin
 Get the Rareware
 Coin
 Get the Camera
 Original Donkey Kong
 Game
Get the Nintendo Coin
To get the Nintendo Coin you need to go to the original Donkey Kong mini-game. If you beat 4 levels with one life you will get a golden banana. If you beat it again you will get the Nintendo coin.
Credit Goes To: Darius Yao via IGN 64

Get the Rarware Coin
To get this coin, you need to get 5000 points in the arcade game Jetpack.
Credit Goes To: Darius Yao via IGN 64

Get the Camera
First you need to have Tiny and need to have her abillity to shrink in size. When you have all of that, get Tiny and swim to the island that looks like a big fairy. Look to the side of that island and there should be a Tiny barrel. Jump inside and you will shrink. Run to the front of the fairy and there is a hole. Go inside and there will be a big bannana fairy. Talk to her to get the camera.
Credit Goes To: Jeremy via IGN 64

Original Donkey Kong Game
In the level in K.Rool's ship, Have D.K. learn the move of pulling a lever (from Cranky). Then go down the crates, left, up a rope (that's wooden), then follow the pipes to a room with a lever. You will see an arcade machine next to the lever. Pull the lever then the arcade machine will turn on. You are now playing the original Donkey Kong.
Credit Goes To: Mike L. (lemus@access1.net via) IGN 64