Ike (FE10)
Good atk, spd, def, and avo. Right from the start, he's extremely durable and has great offense, and he only gets better. Not being mounted isn't even bad since most of the mounts have pretty severe problems: horse units can't cross gaps, rivers, etc., and pegs get wtfpwned by bows. But he would be better if he were on a wyvern. Those things are OP'd.
Anyway... Ike also makes whoever he supports with much more durable thanks to his earth affinity.
And he also has 3 leadership stars, making him pwn even more.