Benjamin Kennicott produced the first critical edition of the Masoretic Text, with variants from 615 Hebrew manuscripts and 52 early printed editions. His publication also includes the Samaritan version of the Torah in parallel columns to the Masoretic text, and all variants are indicated.
Because Kennicott's critical edition contains a magnitude of information, collated from hundreds of Hebrew manuscripts, it is a valuable resource for anyone interested in the study of the Masoretic text. It also bears witness to the incredible care and precision by which the Masoretic preserved the Hebrew text of the Bible.
Originally published as "Vetus Testamentum hebraicum cum variis lectionibus" - "The Hebrew Old Testament with variant readings."
Volume I: Genesis - Second Kings