My favorite is 3N37, both for its stellar performance, and the smell after ignition.
I have made maybe a million 40 S&W rds using Power Pistol.
I have made maybe half that amount using WAP (man I still gotta lotta WAP. Available equivalent = Ramshot Silhouette).
Did you mean "choose only one?" Power Pistol.
"all my ammo is mostly retired factory ammo"