18. C-3PO
A protocol droid created by Anakin Skywalker who was present for many of the most important events of the rebellion and New Republic area, C-3PO's ability to speak millions of languages was instrumental in the attack on the shield generator at the Battle of Endor and numerous other times throughout the saga. C-3PO is perpetually complaining about anything and everything, with his job being to essentially annoy all the other characters including his buddy R2-D2. His apprehension makes sense when you remember that he spends most of the original trilogy being pulled apart or blown up. In many ways he stands in for the audience as he's probably the character that is most like what the average person would be like in similar situations and he's a nice contrast to the larger than life characters that inhabit the rest of the universe. Finally, without him we wouldn't ever know what R2-D2 was talking about or what the odds are for making it through an asteroid field, making him the best walking exposition machine since Morgan Freeman.