The Elder Scrolls IV: Oblivion Cheats

Achievements:
Complete the following achievements to unlock the indicated number of Xbox Live Gamerscore points.

Escaped the Imperial Sewers (50 points): Escaped the Imperial Sewers, Main Quest Beginning.
Closed an Oblivion Gate (50 points): Closed an Oblivion Gate, Main Quest.
Located the Shrine of Dagon (50 points): Located the Shrine of Dagon, Main Quest.
Delivered Daedric Artifact (50 points): Delivered Daedric Artifact, Main Quest.
Destroyed the Great Gate (50 points): Destroyed the Great Gate, Main Quest.
Champion of Cyrodiil (110 points): Completed the Main Questline.
Murderer, Dark Brotherhood (10 points): Join the Dark Brotherhood.
Slayer, Dark Brotherhood (10 points): Reached Slayer rank in the Dark Brotherhood.
Eliminator, Dark Brotherhood (10 points): Reached Eliminator rank in the Dark Brotherhood.
Assassin, Dark Brotherhood (10 points): Reached Assassin rank in the Dark Brotherhood.
Silencer, Dark Brotherhood (10 points): Reached Silencer rank in the Dark Brotherhood.
Speaker, Dark Brotherhood (10 points): Reached Speaker rank in the Dark Brotherhood.
Listener, Dark Brotherhood (50 points): Completed the Dark Brotherhood Questline.
Pit Dog, Arena (10 points): Joined the Arena in the Imperial City.
Brawler, Arena (10 points): Reached Brawler rank in the Arena.
Bloodletter, Arena (10 points): Reached Bloodletter rank in the Arena.
Myrmidon, Arena (10 points): Reached Myrmidon rank in the Arena.
Warrior, Arena (10 points): Reached Warrior rank in the Arena.
Gladiator, Arena (10 points): Reached Gladiator rank in the Arena.
Hero, Arena (10 points): Reached Hero rank in the Arena.
Champion, Arena (10 points): Reached Champion rank in the Arena.
Grand Champion, Arena (50 points): Completed the Arena Questline.
Pickpocket, Thieves Guild (10 points): Joined the Thieves Guild.
Footpad, Thieves Guild (10 points): Reached Footpad rank in the Thieves Guild.
Bandit, Thieves Guild (10 points): Reached Bandit rank in the Thieves Guild.
Prowler, Thieves Guild (10 points): Reached Prowler rank in the Thieves Guild.
Cat Burglar, Thieves Guild (10 points): Reached Cat Burglar rank in the Thieves Guild.
Shadowfoot, Thieves Guild (10 points): Reached Shadowfoot rank in the Thieves Guild.
Master Thief, Thieves Guild (10 points): Reached Master Thief rank in the Thieves Guild.
Guildmaster, Thieves Guild (50 points): Completed the Thieves Guild Questline.
Associate, Mages Guild (10 points): Joined the Mages Guild.
Apprentice, Mages Guild (10 points): Reached Apprentice rank in the Mages Guild.
Journeyman, Mages Guild (10 points): Reached Journeyman rank in the Mages Guild.
Evoker, Mages Guild (10 points): Reached Evoker rank in the Mages Guild.
Conjurer, Mages Guild (10 points): Reached Conjurer rank in the Mages Guild.
Magician, Mages Guild (10 points): Reached Magician rank in the Mages Guild.
Warlock, Mages Guild (10 points): Reached Warlock rank in the Mages Guild.
Wizard, Mages Guild (10 points): Reached Wizard rank in the Mages Guild.
Master-Wizard, Mages Guild (10 points): Reached Master-Wizard rank in the Mages Guild.
Arch-Mage, Mages Guild (50 points): Completed the Mages Guild Questline.
Associate, Fighters Guild (10 points): Joined the Fighters Guild.
Apprentice, Fighters Guild (10 points): Reached Apprentice rank in the Fighters Guild.
Journeyman, Fighters Guild (10 points): Reached Journeyman rank in the Fighters Guild.
Swordsman, Fighters Guild (10 points): Reached Swordsman rank in the Fighters Guild.
Protector, Fighters Guild (10 points): Reached Protector rank in the Fighters Guild.
Defender, Fighters Guild (10 points): Reached Defender rank in the Fighters Guild.
Warder, Fighters Guild (10 points): Reached Warder rank in the Fighters Guild.
Guardian, Fighters Guild (10 points): Reached Guardian rank in the Fighters Guild.
Champion, Fighters Guild (10 points): Reached Champion rank in the Fighters Guild.
Master, Fighters Guild (50 points): Completed the Fighters Guild Questline.

Unlimited Gold (Glitch):
Go to the Talos Plaza District of the Imperial City. Find a house owned by a men named Dorian (Dorian's House) in the southeast section of the district. Break into his house and find him. When he tells you to leave, kill him. To loot him, do not press X to take all. Instead, take each item individually, finishing with the gold, which will not run out once it hits 8 pieces. Just keep selecting the gold he is carrying and keep pressing A as usual. Do this repeatedly, and the number of gold pieces remaining will freeze when it gets down to 8 gold pieces. It will not go any lower, but will just keep giving you as much gold as desired.

Improved gold glitch:
The gold glitch cheat is currently on here but it is possible to improve on this. You don't need to break in if you enter Dorians house in the day. He will still tell you that he doesn't need any more friends. Use Persuade and bribe him up as high as you can and then kill him. Then loot him item by item saving the gold till last where you will get anywhere from 110 -200 gold at a time for as long as you continue pressing A rather than 8 gold at a time. Giving him gold before you kill him makes it much easier to acumulate a large amount of gold quickly.
(supplied by: Fotograffiti)

Useful advice:
This isn't so much a cheat or clue, but just some useful advice. If you are just starting this game out, or having some real problems, your best bet is, after you get out of the Imperial Sewers, is to not look at the Main Quest at all. You should attempt/try to beat all of the Mages, Fighters, Thieves Guilds, Dark Brotherhood Missions, and Arena Missions. Doing this would bump your level up from 3 to 30, depending on how you work at it. Also adding in Daedric, Master Trainer, Miscellaneous, Freeform Quests would surely bump you up a ton of levels. This would leave you left with only the Main Quest, which you could breeze by. I only did a few Freeform and Miscellaneous Quests, and I did all of the Thieves Guild and Dark Brotherhood Missions, and I was equipped with a way higher level than the first time around, new enchanted/unenchanted weaponry, jewelry, and clothing, and also allowed me to explore many new places that I could fast travel to when it came to that in the Main Quest.
(supplied by: niptuck117)

Duplicating Items:
1. Take your bow and pull an arrow back.
2. Press B while holding your arrow back.
3. Press another set of arrows until it says you cannot switch arrows.
4. Pick an item: ex. apple
5. drop the item.
(supplied by: Bangin)

Duplicate trick:
If you need to duplicate something and have too many arrows like if you have 100 arrows and you only need 70, equip all your arrows and drop the amount you need. Then equip the rest of them and pick up the ones you dropped. The one that you dropped will be equiped and the ones you equiped before will be unequiped and now you can use the duplicate the rite amount of items you need.
(supplied by: Bullyboy)