This is if I could somehow have them downloaded into my brain, and then be able to speak/read them flawlessly.

I already know English (of course) and German, though I can only really read and understand the latter these days, so I'll need a complete redownload of it.

Other languages...

Languages of today:

• Chinese
• French
• Greenlandic
• Italian
• Japanese
• Portuguese
• Russian
• South Korean
• Spanish

Other cool ones to know:

• Ancient Egyptian
• Latin
• Old Norse
• Sumerian

Fictional languages:

• Goa'uld (Stargate SG-1)
• Klingon (Star Trek)
• Elvish (Lord of the Rings)