Nature and Growth of Modern Mathematics by Edna Kramer. If you love history and mathematics, this is a good combination from what I remember, sort of alternating between historical placements and biographies with actual mathematical content explained.

I read this decades ago before I learned advanced mathematics and I found it enlightening and inspiring at the time though I have not revisited it since though it is a cherished memory. The book's age prevents it from covering the many modern innovations since.