Well I have 2-3 soul reapers which are my favorites.^^ Captains Toshiro Hitsugaya, Maiyuri Kurotsuchi and Byakuya Kuchiki, cause their bankais are awesome. ^^ Captain Hitsugaya's Daiguren Hyorinmaru, captain Kurotcuchi's Konjiki Ashisogi Jizo and captain Kuchiki's Senbonzakura kageiyoshi nad it's 3 forms: Gokei Senbonzakura Kageiyoshi, Senkei Senbonzakura Kageiyoshi and Shuuhei hakuteiken. Truly awesome!
Stark is my favorit espada! It took three captain level opponents to beat him and the only reason he lost was because of the cheap shot shadow blade, that had to hurt, and that color game. Plus, he is so laid back just like me.
I can't really choose a favorit soul reaper though because I got five.