I don't like slow characters with little to no team utility.
Xiao lacks in the team utility but he's super fast (me preferred style of play) especially when paired with another anemo character. His burst also gets through every shield in the game.
Ganyu has the highest DPS potential. Can do damage at range. Her burst can be used for reactions and her elemental skill taunts
Diluc is raw damage as well as elemental reactions enabler
Keqing is probably the most fun character to play with. She's super fast and feels like a Devil May Cry characters
and that's just DPS characters
my utility ones;
Venti hits +20K with his elemental skill if I hold. +13K on quick press on a 6 second cooldown.
Albedo hitting +8K with his skill on 4 seconds cooldown and +12K every 2 seconds with sola isotoma once the skill is on the field. He augments everybody's damage output.
Jean hitting +11K on a 6 seconds cooldown with her skill (and she's only level 60)
this is on world level 8 against level +90 ads when my team is hovering around level 70 with only a couple 80 units.