I primarily use mouth calls and push-pins, but when I do use a pot call, it depends on weather conditions:
Clear/Calm day: Slates are my go to pots, ie Cody Spec 1 or World Class, Platz Maple Slate (Snakewood or Black Night Striker)
Windy/Wet day: Screamin Demon Crystal, Brad Roberts Bronzed Glass (Weatherproof Carbon striker, Snakewood if dry)