Minecraft is an indie sandbox video game based around building structures in a voxel based world. Contained within is a survival mode, as well as a free play build mode.
Pro Great creativity tool
If you prefer building, creative mode is the way to go. It immediately gives you unlimited blocks, the ability to fly, and immortality. This allows you to easily build anything you want without worrying about height or enemies. Things like giant castles, villages, roller coasters, and even unique builds such as the Enterprise from Star Trek. You can really let your creativity loose.
Pro Amazing extended community
The community surrounding this game is huge due to its popularity. There are lots of servers and projects revolving around it that allow for so many different choices in how one wants to play and who they want to play with. From crafting guides/videos, themed servers and YouTube play sessions, there is enough out there to help one find what they are looking for.
Pro Randomly generated worlds and distinct locations keep the gameplay fresh
Each new world is randomly generated, making for a different experience every time. There can be plains, rivers, beaches, ravines, giant mountains, hidden villages, and a lot more.
There are also 38 biomes, which includes snow, desert, forest, swamp among others. Each one has its own set of unique blocks, plant life, and creatures.
You won't get tired of exploring above ground or underground because every location will seem new and exciting.