For light travellers, we recommend Handpresso, Minipresso, Espro Travel Press, Cafflano Klassic or Aeropress. These units are all relatively light and compact, taking up very little space and your bag.
If you’re looking to get an unplugged coffee maker for travel where space/weight isn’t an issue (camping/glamping) we recommend looking at the ROK espresso maker.
See also Which coffee maker should I choose?