The Legend of Zelda: Ocarina of Time

200 Rupees from the Skull Kid (adult):
As Adult Link, enter the Lost Woods and turn left. A Skull Kid stands on a tree stump. When he comes at you, defeat him quickly (the Biggoron's Sword makes it much easier). If you beat him before he disappears, he leaves a huge Rupee worth 200. You can come back and do it again as often as you like.

500 Rupees for the Bunny Hood:
As Young Link, get the Bunny Hood from the Happy Mask Shop (after selling the Keaton Mask, Skull Mask and Spooky Mask). Wear it and talk to the man running laps around Lon Lon Ranch in Hyrule Field. Sell it to him for 500 Rupees (get the Giant's Wallet first, or you can't hold it all).

Unlimited Rupees:
Get all 100 Gold Skulltula tokens and talk to the last cured family member in the House of Skulltula in Kakariko Village. He gives you a Gold Rupee. Leave the house and go back in to get another.

Sell fish and bugs:
Catch a fish or a bug in a bottle and sell it to the man who wants to buy things (Castle Town Market as a child, Kakariko Village as an adult). A bug pays 50 Rupees and a fish 100 Rupees.

Hidden chests in Goron City:
- Smash the brown rocks all the way to the left in the boulder room with the Megaton Hammer to find a chest with a Gold Rupee.
- Play the Song of Storms in the circle of rocks outside Goron City. A hole opens with a chest below.

Power Stab:
Hold R and press B to stab. The stab has the power of the attack you used just before it, so a Deku Stick jump attack followed by stabs gives Deku Stick power without using up Deku Sticks.

Keep your tunic and shield:
When a Like-Like is about to eat you, equip the Kokiri Tunic and the Mirror Shield. They can't be bought, so the Like-Like can't take them.

Giant enemies:
Kill some enemies many times in a short while and a giant version appears, e.g. the Stalchildren on Hyrule Field at night, the Guay at Lon Lon Ranch and the Leevers at the Desert Colossus.

Mario picture:
When you first meet Zelda in the castle courtyard, look in the last window on the right: it shows pictures of Mario and his friends. Shoot it with the Slingshot for a red Rupee (20). Shoot the window opposite and a guard throws a bomb out at you.

Fix a broken sign:
If you have cut down a wooden sign, play Zelda's Lullaby (or leave the area) and the sign puts itself back together.

Fairies from Gossip Stones:
Play Zelda's Lullaby or the Song of Storms in front of a Gossip Stone and a fairy comes out.

Scarecrow melody after the credits:
If you played a melody for Pierre the scarecrow in Lake Hylia as a child, wait several minutes on the "The End" screen. Your melody plays on the ocarina, and later again on another instrument. N64 version only.

Stone of Agony:
Collect 20 Gold Skulltula tokens and visit the House of Skulltula to get the Stone of Agony. With a Rumble Pak it makes the controller vibrate near hidden holes.