I don't feel like sifting through the post's :P But hopefully someone mentioned the following.
Ratchet and Clank Futures!!!! It's amazing ^^ Plenty of exploring, and while it's not 1 open world, you do get many amazing ones to romp around in :)
Uncharted >: ) It's amazing!
Warhawk! Is a 3rd person online only game, but the worlds are huge and traversing them is entirely too awesome :)
Not quite "adventure" but I thought Folklore was fantastic! It's more along the action RPG type, but a totally awesome experience none the less ^^
From 0 to KICKASS in .stupid seconds.