There is no right or wrong answer, its the software that you like to use.
DPP is free
LR is good, and excells at organizing your images
DXO renders excellent images without you needing to tweak them
Phase one is very good
Aperture is very good
Photoshop is very good
Many love Gimp
Many love ACDSee
Sorry if I missed any, but these companies would not be producing software unless they had many faithful users, so best is a very relative and subjective term.