I would love to know the answer to your question. On the one hand, it's too subjective to answer, one student's Spivak is another's Apostol; on the other hand,

I would love to know the answer to your question. On the one hand, it's too subjective to answer, one student's Spivak is another's Apostol; on the other hand, certain books just seem special in an almost objective way and rise above the scores of other books on the subject. There is this: https://mathblog.com/mathematics-books/ https://mathblog.com/mathematics-books/ which looks like a pretty well curated list