Which systems should I bring!!?

[ninjainspandex]

3DS, GBA SP, and PSP. That's the combo that gives you access to the largest number of games.

I second this. Bring these three and you will have access to all the portable games in your collection.

the GBA emulator on the psp is very good the only two games i had trouble playing were the two golden sun games, so unless you are planning on playing those leave the gba at home.

[8bit]

Bring an Atari Lynx. Best. Games. Ever.