YSEQ specializes in advanced Y-DNA sequencing and analysis, offering high-resolution testing that provides in-depth insights into Y-DNA haplogroups and subclades. It's an excellent resource for researchers looking to dive deeper into paternal lineage analysis.

Family Tree DNA is one of the leading companies offering Y-DNA testing services. They provide detailed haplogroup assignments and a wealth of genealogical data to help you trace your paternal lineage.

YFull offers comprehensive analysis of Y-DNA test results, including detailed phylogenetic tree analysis and mutation rate estimates. It provides deep insights into your paternal ancestry.

ISOGG provides a comprehensive Y-DNA haplogroup tree along with resources and research for genetic genealogy. It's an essential resource for both amateur and professional researchers.

YHRD is a specialized database that collects Y-chromosome haplotype data from populations around the world. It’s widely used by researchers to study genetic diversity, migration patterns, and haplotype distributions.

23andMe provides direct-to-consumer genetic testing. While primarily focused on autosomal DNA, 23andMe also offers insights into paternal ancestry for males, including basic haplogroup predictions.

MyHeritage offers DNA testing services along with powerful tools for genealogical research. In addition to providing ancestry estimates, they help build and explore family trees using historical records and genetic data.