R2-D2. It's amazing how much personality is conveyed through him via simple movements and 'bleep' sound effects. He has no voice or face, yet he still manages to ooze tons of personality. The facets of his personality I love most are his courage and loyalty - whatever the situation is, whatever the danger, Artoo always rushes to the aid of his friends and always comes through for them. Seriously, in how many times in the saga do main characters have their asses saved by the little droid? I'd go as far as saying R2-D2 is the most useful character in the series. To sum Artoo up I'd call him a 'feel good character'. He's a character that doesn't have to be taken too seriously, but you'll always find yourself smiling, laughing and cheering when he's on screen. For this reason R2 centred scenes (especially when he's with C3-PO where we see the best comedy in the series) are some of my favourites (the droids arc even happens to be my favourite arc in TCW).