Uranometria [both hemispheres obviously] is my go to atlas. Sure there is Millenium, but frankly, it looks like uranometria with a tad fainter stars. I'd never give mine up, and I'd nevber feel the need for another. When I need pinpoint - faint starfield location accuracy - its all online.

I simply dont see a use for anything else. Ofcourse, Ive got the book that identifies all the deepsky objects which makes this a three volume set.

Pete