Favorite smoothie recipe?

I don’t know if this is technically considered cooking, but I can’t make a decent smoothie to save my life. I’ve had one on repeat, which is a frozen banana, milk, sunflower seed, butter, oats, and vanilla. It’s not super sweet, and it tastes like a chocolate chip cookie. sometimes I’ll even put dark chocolate chips in it. But I need to branch out and get other kinds of produce in my smoothies and would love if anyone shared their favorites.