What would you want offline to be without internet for a year?

What would you want offline if you were going to be without internet for a year ?

Suppose you won't have internet, but you will have lots of computing power and 20 terabytes of storage space. What do you cache offline for a year ? Your goal is to learn, explore, play with the data.

To start with:

1. Wikipedia text: 20 gigabytes

2. Hacker news: 6 gigabytes

3. Reddit:

4. All Debian packages with source:

5. All stack exchange data dumps

What else ?