If your priority is reliability, industry consensus points to these "end-of-branch" versions. They are typically the final, most patched releases before a major architectural shift.
Better for safety applications with L6x or L7x processors, but only if you cannot use v20.
Your software's major version must exactly match the controller's firmware major version (e.g., software V30 for firmware V30.xxx).
This is a common question, but "better" in RSLogix 5000 depends entirely on and what hardware (firmware revision) your CompactLogix or ControlLogix controller uses .