You fancy naval adventures? Try this one for a flooded world that has but a few, small, hard to find islands.
You like spelunking? Try out these massive caves and ravines. Bonus points for extra curvy rivers.
For a seed that is just nice and breezy and offers plenty of pretty examples of all the great things Minecraft can do, try this one.
Seed: The Miner
Try this if you want to build a sled and speed across the taiga, cause this giant winter biome will see you travel overland for days.
Nine villages in close proximity. You will never be lonely again.