It is really hard for me to pick my favorites, because I don't have any cichlids right now I don't like. For personality I think my favorite is my Crassipinnis Oscar. Although I think he is beautiful as well.
My Blue acara also has a great personality, eats from my fingers, is dominate, but extremely peaceful.
I also really enjoy my Satanaperca leucosticta.
In beauty my Synspilum pair wins it.
For just downright cuteness you can't beat Keyholes, or C. Nanoluteus.