Spawn in taiga forest very close to a realtively large village with blacksmith. The chest of the smithy holds some excellent stuff for you to grab:
Right under the village at -263 49 394 there is a spider spawner with a chest holding 1 iron horse armor.
A bit further at -306 48 370 you will find a zombie spawner with a chest containing:
Both of these spawners are connected with an abandoned mineshaft that has a fantastic treasure chest at -263 38 375 with the following loot inside:
Share your own favorite Minecraft 1.10 seeds in the comments section!