IGN Anime Club gives a rundown of "moe" characters in anime and explains why Star Wars' BB-8 might be a great example.
Anime mentioned in this episode:
Harmony Toradora! Voices of a Distant Star She and Her Cat Space Patrol Luluco Kiznaiver Kill la Kill Sailor Moon K-On! YuruYuri Nichijou Lucky Star Hetalia: Axis Powers Gurren Lagann Star Wars (not an anime, but it's important) Himouto! Umaru-chan Puella Magi Madoka Magica School-Live!! Shirobako