R2-D2
A reliable and versatile astromech droid, R2-D2 has served Padmé Amidala, Anakin Skywalker, and Luke Skywalker in turn, showing great bravery in rescuing his masters and their friends from many perils.
C-3PO
C-3PO longs for more peaceful times, but his continued service to the Resistance and his knowledge of more than seven million forms of communication proved useful over the years.
BB-8
A skittish but loyal astromech, BB-8 accompanied Poe Dameron on many missions for the Resistance, helping to keep his X-wing in working order. He later helped Poe Dameron and Rey on their quest to locate Luke Skywalker.
D-O
Cobbled from odds and ends in the workshop of a droidsmith, little D-O is an impressionable little roller that becomes fixated upon BB-8.
R2-Q5
R2-Q5 is a black and bronze Imperial astromech droid. As a "dark twin" to R2-D2, it performed maintenance and stored Imperial data. Ultimately, it was destroyed in the Battle of Endor.