Missy was an innovator. She gave us a wave of some of the most audacious classics.
Nicki will be more memorable as she is more of a brand in comparison. She's the only relevant female rapper that pop radio will even use these days. There's no one to really compare her too (Hence Lil Kim's meltdowns)
Missy is already a certified legend. I love Onika to death but she's not quite there yet. I think it's possible that she could be up to Missy's status at some point in her career though. She already basically has a business empire and brought female rappers back into the conversation a couple years ago.
Nicki easily. She is the most famous and successful female rapper of all time and will become the standard that others are measured to for years to come. Missy is already forgotten about by most people.
missy's hits are TIMELESS. the rain (supa dupa fly), work it, get ur freak on, lose control. plus she was always acknowledged for her creative music videos.
what does nicki have? super bass? starships? nicki is talented but she's not quite there yet, sorry.