Just what the title says:
One word movie titles
Birds
MLB players by surname
Personality traits
Battles
Movie comedies
Capitals
Musical instruments
Musical composers
TV series
Movie titles spelled backwards
Animated characters
Characters in any incarnation of “Star Trek”
Characters in any incarnation of “Star Wars”
Brand names
Weather, whether you like it or not
Presidential-campaign-related words
D&D monsters/creatures
Authors
Anything associated with 9/11/2001
Composers
People in the Bible
Notable historic ships
Musical instruments
Important world cities spelled backwards
People or terms in motorsports
Album titles
Astronomical terms
Aeronautical terms/people
Color my world
Actresses
Hard rock/metal bands/songs
Rulers and what they ruled
Things to do on Leap Year Day
Things in your fridge
Romantic destinations
Simpson’s people/places/things
Mythological beings
Songs and a musical group that sings it that start with the same letter
Sports team names (any sport, any league)
Science fiction characters - any fandom or source
Historic Women
Wizards, Witches & Magic
Diseases and medical disorders
Video games/characters/things
Childhood
Foreign language films
Tough guys, real or fictional
Vehicles & Other Modes of Transportation
Next up, smart people. Real or not.
Short people – well-known for something besides being short
Works of Literature
Boardgames
Law enforcement - people and things
Words that start and end with the same letter
Aircraft manufacturers, past or present
Tools
Anything Green
Comic books people ‘n’ stuff
Things used in the medical field
Electronics/electricity
Ugly-sounding words
TV Series
Sci-fi novels
Chemistry!
Heads of state (alphabetical by first or last name)