Minecraft is really good. There are lots of users playing it and you can also join other peoples games and create buildings or even destroy their buildings on their saved world.
Good seeds vary between different Minecraft versions.
You will have to rebuild them.
Planet Minecraft and Minecraft Wiki are two sites i can think of.
Try using a map editor, like MCEdit.
Every Minecraft seed has water.
Minecraft Fallen Kingdom parody (from CaptianSparklez).
NuclearPixel
minecraft is dogwater
Some good minecraft minigames are Survival Games, Spleef, CTF (Capture the Flag), Paintball, and Parkour.
Modded is a great minecraft xbox 360 seed and worstseedever
Notches other minecraft creators ones minecraft experts and mine.lol there are too many but another good one is good games spawn points server.