Legend of Spyro: Dawn of the Dragon - Maximum XP

Unlimited Life:
Pause the game, then hold LT and with the left stick press Right, Right, Down, Down, Left.

Unlimited Mana:
Pause the game, then hold RT and with the left stick press Up, Right, Up, Left, Down.

Unlock all Elemental Upgrades:
Pause the game, then hold LT and with the left stick press Left, Up, Down, Up, Right.