I built a tool a ways back. It is an excel spreadsheet. It has columns for:
Name
Source
Intelligence
Charisma
Wisdom
Sanity
Honor
Confidence
Agreeableness
Conscientiousness
Extravertness
Openness
Stress Tolerance
Melodrama
I treat these like ability scores (ranked 3 to 30). When I see a TV, movie, etc... character I enjoy, I drop them on this sheet and assign them scores for some or all of these categories. I really only use 3, 7, 10, 13, 16, 20, 25 and 30 on the chart. I am trying to remember where all the categories came from, but I can't for the life of me.
Then, when I need an NPC personality and nothing jumps out at me, I filter it down to the right range for the most relevant categories for the NPC and select one to use. I then do my best impression of the character, which is usually unrecognizable, but reminiscent from a style perspective. When writing the adventure, I can just drop in the name in brackets next to the NPC in the notes and I have an instant personality all ready to go.
It has about a thousand characters on it now from Buffy, Marvel, GoT, Gilmore Girls, Critical Role, 1980s Cartoons, Die Hard, the Sopranos ... anything I've seen, and in some case read.