The best unit is always the unit you enjoy playing, and also depends on other factors such as your personal artifacts, the weapons you own, the teams you can build and your constellations.
This tier list is not pulling advice.
• All units are C0R1 with level 10 talents in their best teams
• Units are sorted alphabetically within their tiers
• This isn't an exhaustive list of every unit in the game
• DPS and Off-field DPS sub-categories are limited to C0R1 5-stars (no 5-star constellations)
• Combat considerations we touch on:
• Onfield damage dealers don't want to build high energy unless they are burst dependent (e.g. Cyno, Raiden Shogun)
• Ease of play refers to simpler gameplay or low inputs (e.g. button mashing vs jump cancels)
• Elemental application (e.g. Hydro application) is important for reaction teams.
• Personal damage, team damage and team damage distribution are considered.
• For sustain units, we prioritize team healing and shield duration.
• Combat categories:
• DPS: On-field damage dealers.
• Off-field DPS: Damage dealers who do the majority of their damage off-field.
• Buffer: Units that give offensive buffs and/or team utility - energy generation, element application, enabling team archetypes, etc.
• Sustain: Healing or shield capacity, with team utility as a major consideration.
• Overworld categories:
• Running: Speed and sustained duration of crossing flat terrain
• Flying: Speed and sustained duration of crossing gaps or large distances in the air
• Swimming: Speed and sustained duration of specifically crossing bodies of water
• Climbing: Speed and sustained duration of climbing cliffs and mountains