Minecraft by Mojang
If you do not know what Minecraft is, you should not be on this website, but for the purpose of being nice, Best Indie Games will talk about it anyway.
Minecraft, developed by Mojang, is an open-world, sandbox game, much like Terraria, that was release in 2009 on PC in the TIGSource forums. Over the course of its journey, Minecraft exploded within the indie games community to become one of the greatest success stories for an independent studio.
The entire world is broken down into cubes, which allows players to mine resources to build weapons, clothing and shelter in the most creative ways possible. The gameplay is taken from the like of Dwarf Fortress and Infiniminer, both successful sand-box games.