For me it’s the Greenes–Herschel and Beth. The former’s calm and wisdom (after season 2) was a comfort; he was much less annoying than the other peace-loving characters. The latter was (until her moral corruption in the hospital) also sweet and lovable, and I miss the occasional song.
I enjoy her acting and singing, but she is beautiful rather than hot. Michonne inspires lust; Beth is more like a painting. Maybe that’s because she trips my big brother reflex, I dunno.