Because you like Rose Tyler in Doctor Who
The only defense Earth has against alien invaders are giant robots in the hands of pilots like Kaworu. See them in Neon Genesis Evangelion.
Ezio Auditore Da Firenze is a little short-tempered, a lot fun-loving. See them in Assassin's Creed Series.
His superiority complex coupled with his bitter desire for revenge makes Vegeta a formidable foe. See them in Dragon Ball Z.
Fox McCloud leads a team of pilots through the Lylat System in search of the evil genius Andross, the villain that killed his father. See them in Star Fox.
Dante Alighieri is a crusader fighting his way to absolution. See them in Dante's Inferno.
Daring on a bike but haunted in his personal life, even Johnny Blaze isn't fast enough to outride his past. See them in Ghost Rider.
Ratchet is a shoot-first, ask-questions-later, and then-shoot-again kind of lombax. See them in Ratchet & Clank.
While his twin tries to save lives, Millions Knives does the best to end them. See them in Trigun.
Spyro the Dragon loves getting into trouble around the Dragon Realms. See them in Spyro the Dragon.
After Rintarou Okabe develops the Phone Microwave, some of his fantasies start to seem uncomfortably real. See them in Steins;Gate.