Griffins and elves are definitely the best, but it's hard to say who's better.
I voted for griffins, but I also really like elves.

In a 1-on-1 fight, it's clear that griffins would crush elves, even though elves might get two shots in. (Griffins have more health, elves have no melee damage, and griffins have a constant counterattack – that's a powerful combination.)
But in an army battle (especially if the ranger has a good strategy), if you hide the elves behind dwarves with dendrites, they can do a lot of damage.