Depends how far you want to boil it down in order to get to best.
If Kills/Hr is your thing it will be one of FAS/FDL/Python/Corvette, most of us that have one or all of these prefer a particular one, I know i do everything faster in the python than the others but if you had a really non-specific pilot who was extremely skilled i'd think it went FAS/FDL > Corvette > Python, for most its simply the one they prefer out of that list.
If Kills/Hr is your thing it will be one of FAS/FDL/Python/Corvette, most of us that have one or all of these prefer a particular one, I know i do everything faster in the python than the others but if you had a really non-specific pilot who was extremely skilled i'd think it went FAS/FDL > Corvette > Python, for most its simply the one they prefer out of that list.