For me ZIP and H110.
I also use Bullseye, Unique and 2400. ZIP covers most loads for 38 Special, 357 Mag and 45ACP for me. H110 is reserved for full house loads in the 357. I can't think of any loads for those 3 calibers I can't duplicate with ZIP instead of Bullseye or Unique. 2400 will load hotter rounds than ZIP but that's not in a area I care about. I seem to be using loadings from mild to medium or full house H110.
I also load Cowboy in 38 & 357 with ZIP. It's clean and economical. The only drawback is that it's denser than Bullseye. I think I could triple charge a 38 with it easily. If I ever use up the ZIP, I'll probably go to Trail Boss for Cowboy just to fill the cases.