I mostly use Gravity standard 2mm. However, I also have a cool metal pick that was made from a 5 Yen coin that I’ve been using more recently, and I’m considering getting a Chinese Feng Shui coin from the company that made these.
For strumming an acoustic, I sometimes use something a lot thinner and more flexible, although nothing specific. It tends to be whatever I have around if I feel the thicker pick isn’t working for me.
Cheers,
Keith