I mean Like the ones with the most pokemon that can have them
As of Generation 8, the three most common Abilities are Swift Swim (43), a tie between Sturdy and Levitate (41), and Keen Eye (40).
Honorable mentions are Inner Focus (36) and Chlorophyll (35).
Levitate (38) Gives full immunity to all Ground-type moves.
Swift Swim (38) Boosts the Pokémon's Speed in rain.
Chlorophyll (35) Boosts the Pokémon's Speed in sunshine.
Studry also comes close with an honorable mention of 32 pokemon.