A few assumptions:

• There will be some sort of PC available, with a keyboard and mouse and speakers, and basic programs to play audio/video, read text/PDF documents, etc. that don't count toward my 1GB limit
• I will have knowledge ahead of time about this PC and its specs, OS, installed programs, etc.

First, I'd make sure to include a stripped down version of 7zip, or whatever compression I use (y'all don't wanna get on there and realize you can't decompress your files). Hopefully only a few MB for a CLI utility.

Second, I'd include a decent library stored in a compressed text format. Some fiction, some non-fiction, classics, some of my favorite series, a bunch of "Intro to ___" type of books, that kind of thing. Probably up to 50MB or so.

Third, I would include some low-quality audio of some favorite music as well as a few audio books. Maybe 200MB or so.

Fourth, I'd include a copy of a simple game engine system (maybe something like libgdx) as well as Inkscape, and whatever compiler I would need to create programs/games for my PC, and relevant documentation. This would give me both a creative outlet, and allow me and my companion to make new games for each other to have something novel. Hopefully around 100 or 200MB.

Depending on the size, I might also consider including something like FruityLoops, again to be able to create new content. Ideally something that's 100MB or so.

With whatever space I have left (300 or 400MB-ish), I'd include things like emulators and a couple favorite older games (Lord of the Realms 2 comes to mind) that have good replay value and would be small enough to fit. Ideally some multi-player options as well (assuming a shared keyboard).

Without previous knowledge of the available PC, I'd include multiple builds of 7zip for most common architectures, and prioritize the books and audio. Maybe bring a couple variants of GCC and minGW (if I can write programs, I can eventually replicate lots of the other software).