If you want to find the answers - remember it may spoil the game - check the text here...
DOOR ONE - It's surprising how early you'll find the first Demon Door in Fable 3, you'll stumble upon it in the Mistpeak section of the second mission. The Mistpeak Valley Demon Door will teach you something about the riddle of the Demon Doors in Fable 3 - they're easy. This time he simply wants to see the passion of two Heroes. The heroes he wants to see must be "live," the AI counterpart won't do. You'll need to bring another Hero to the doorstep via either Xbox Live or local co-op. Use the Hug, Kiss and Tickle expressions from the Lovers Expression Pack (available on the Road to Rule) - make sure both Heroes have this Expression Pack also. The expression pack only costs five Guild Seals once open grab the Legendary Weapon inside.
DOOR TWO - The Brightwall Village Demon Door - pessimistic about the world. Just bring him something that illustrates that innocence and purity still exist. The Brightwall Village Demon Door then opens revealing 25 Guild Seals and three Summon Creature potions.
Q: What's pure, innocent, small and runs around Albion
A: children.
So, bring him a child, one of your own or one you've adopted from the Bowerstone Orphanage Note: you can only adopt a child after you've restored the Orphanage late in the game. If you're the type that can't wait until the end of Fable 3 to open up the second Demon Door, get married and have children. Then open the Brightwall Village Demon Door number two.
DOOR THREE - The Mourningwood Demon Door, in the swampy area on the way to the sewers of Bowerstone. This Demon Door is looking for "an enormous weapon greater than anybody else's" It's not that complicated but requires some combat: you'll need to show him a maxed-out Legendary Weapon. Achieve this by meeting 3 distinct objectives that are based on the Legendary Weapon you have equipped. You also need to purchase either the Melee or Ranged Level 5 upgrade available only at the very end of the Road to Rule. Then open the Mourningwood Demon Door and reap the rewards: a Military costume and a Summon Creatures potion.
DOOR FOUR - After the Mourningwood Demon Door, come's the Millfields Demon Door. Located in the hillside between the Clixby-Stanners Manor and the Timmins Towers. This is the easiest Demon Door in Fable 3 to find. Taking the basic premise of Fable 3's freedom - appearance and how you define "normal" - it will only open if you "break with society norms". To open Door 4 you must dress ugly and gain a lot of of weight. Ugly clothing is defined by pajamas make sure you color each a different color. Then go mad on food and beer and your avatar's weight meter will swing right. Once you've done this, you'll be able to open the 4th Demon Door. Gaining access to 40 Guild Seals.
DOOR FIVE - In the City of Aurora, you'll find the City of Aurora Demon Door. This Demon Door is easy to open. This door spoke to me in a congratulatory tone and opened automatically into "The Moral View" the old stone ruins were filled with flowers and rabbits. If you've been an utter villain, you'll find a different themed environment altogether. The prize is the same regardless: a Legendary Weapon that's probably the most powerful weapon you've used up to this point in the game.
DOOR SIX - The most puzzling Demon Door - the Sunset House Demon Door, located inside the Sunset House near Mourningwood. Definitely worth opening the reward inside is 1 million in gold! This Demon Door is easy to locate, just to the left of the main pathway. To get your hands on 1 million gold you simply need to be the King or Queen of Albion. The 1 million in gold hidden within this Door will come in handy before the climactic $6.5-million battle. Best hit this Demon Door right after your coronation but before going on the Desert Star Diamond quest.