As the titler says - what is your favorite ink, and why? Does it change with the seasons or the use case?

I can start out. My current favorite is Diamine Oxblood. I'm not really sure why this is, but I like the color and it behaves nicely in my Safari. I also enjoy my Iroshizuko Tsuki-Yo, and I really like this color, but I have not tested this much. But I think it will be good in my AL-Star 2023LE Petrol! 😎