Trailheads we like

Basic Trailheads

Consultant:
https://trailhead.salesforce.com/en/content/learn/modules/consulting_partner_basics

BA:
https://trailhead.salesforce.com/en/content/learn/trails/force_com_admin_beginner
https://trailhead.salesforce.com/en/content/learn/trails/force_com_admin_intermediate
https://trailhead.salesforce.com/en/content/learn/trails/force_com_admin_advanced
https://trailhead.salesforce.com/content/learn/projects/customize-a-salesforce-object
https://trailhead.salesforce.com/content/learn/projects/build-a-simple-flow

More advanced BA:
https://trailhead.salesforce.com/en/content/learn/superbadges/superbadge_lex
https://trailhead.salesforce.com/en/content/learn/superbadges/superbadge_process_automation
https://trailhead.salesforce.com/en/content/learn/superbadges/superbadge-service-cloud-admin-specialist

Really advanced BA:
https://trailhead.salesforce.com/en/content/learn/modules/big-data-strategy

Developer:
https://trailhead.salesforce.com/en/content/learn/superbadges/superbadge_apex
https://trailhead.salesforce.com/en/content/learn/modules/apex_patterns_sl
https://trailhead.salesforce.com/en/content/learn/modules/apex_patterns_dsl