Here is some seeds I have found via the internet, none of these are mine just helping you G's out.

What are Seeds?
"World generation seeds were added to Minecraft on February 23rd as part of the 1.3 update. A seed is a string of characters used to provide a starting point for the terrain generation algorithm when creating a new world.

Using the same seed to generate two separate worlds will generate the same terrain consistently even on different computers. This means that seeds can be shared between players to generate the same world between them. However, the player's initial spawn point will be random."

---

404
404 is a gravel beach near the spawn, you break one block and go under and you'll find useful resources.

Glacier
Glacier spawns you next to a ton of mountains, some of them are partly flying.

gargamel
gargamel spawns you in a cave it's really dark but if you can find a way out you'll be placed in an awesome valley.

Dead Mau5
Dead Mau5 contains multiple things one of them being a little Skeleton Dungeon with Moss Stone, x3 Saddles, x6 Iron, x3 Buckets and x3 Redstone. There is also flying mountains with multiple waterfalls. Also you there is lava so you can easily make Obsidian, then make your portal.

Diamonds, diamonds everywhere!
This seed contains a massive floating mountain above a surface zombie dungeon near the spawn area. The more you move away from the location you'll find other features including a HUGE lava flow.

12345678910
Spawns you near mountains, has an overhanging cliff and wonderful mountain range.

notch
Spawns you near a dungeon with a sand roof, you can easily delete one of the blocks, drop in and get the chest, the chest contains a saddle.

---

User Seeds
Here is a list of seeds that other users have posted on this thread, if you want one to be added, please post and add in a little description if possible.

Quesadila
"Spawns you above 2 spawners (skeleton and zombie) they are directly under the ground at spawn" "also inland is a massive O shaped mountain... it looks amazing "

worstseedever
Spawns you beside a spawer, may want to have Peaceful on!

---

Here are some random seeds I don't have a description of and just found (Not sure if they all work.)
Source for majority for some: [ Register or Signin to view external links. ]
Mojang
WEED
cheesecakefactory
xbox 360
youtube
Cummins Minecraft
Airport
firfar
Mineceaft
177907495
1385327417
MODDED
Vevelstad
Elfen Lied
729
-8388746566455332234
4238342445668208996
965334902297122527
5515274009531393841
Archespore
turnofthetides
worstseedever
beagle bagle
pokeylucky
curtis dent
1420013959
1474776471
1961263745
1541961902
Quesadila
-6362184493185806144
5944220116861330522
-780636540
Roughsauce
Wolf
Diamonds, diamonds everywhere!
Aether Collab
-2608611364321170322
-01556767897
-1293644106920865080
Werewolf
459722261485094655
1363181899730807241
5677344492879191995
5682930821
72164122
2409838883250561605
Wave Race 64
-115144210771600827
-9028489474908844496
9000.1
Dead Mau5
Ausm
-2945350671081178213
Invinsible
3666440496532277820
-442650539972332399
Timestamp: 2011-03-02 06:55:36 U
4042531831790214307
-6555642694674147910
gargamel
-1784338777788894343
Glacier
404

---

Seeds I Have Used
404 - Probably the best for resources.
343 - Snow seed, I like it for the snow and have found some great cave systems.
Glacier - Really nice mountains and is a good seed for a scenic type view.
I suggest you try out these ones, I'll update this part also when I use more and right a description of my own.

---

If you can remember any seeds from 1.6.6 (PC) then they should work on the Xbox 360 version.
Hope that helped a few of you out.

I will also be doing a series called "Minecraft Seed Show" where I go through seeds and show them off in a video, you can find it on mine and my friend's channel: [ Register or Signin to view external links. ] - Record with HD PVR.