The 1.2.5 minecraft seed Old Spice is great. To begin with you spawn near an NPC village that is almost entirely submerged in water. Its coordinates are X: 288 Z: 186. There is a blacksmiths building in the village and it has 3 diamonds in the chest, Bonus!
Nearby the village at X: 196 Z: 121 is a huge pit, and it leads to a cave system that is great for exploring. I only explored for a couple of minutes in the cave and I found some diamonds at X: 200 Y: 11 Z: 13. I am sure there is plenty of other good finds in there for the intrepid spelunker.
A distance away at X: 13 Z: -382 is a second village in a desert biome. There is another blacksmiths chest, but its contents are less exciting than the first.
In the same desert is a 3rd village at X: 119 Z: -675 …thats a lot of villages in pretty close proximity.