I'm looking for something where the main character (or a very important non-primary character -- think Zoro from One Piece) is a supremely powerful individual who's power is almost god-like compared to the everyday people that surround him.

I'm looking for something where the powerful individual is almost indifferent about his power and rarely uses it, but generally only uses it to protect others. He (or she) should be completely unassuming in their everyday life and virtually nobody should know just what they are capable of.

An example of sorts would be the beginning of Dragonball whereby everybody just sees Goku as a non-threatening child full of innocence when in reality he's so strong he beats up dinosaurs for being "not nice".

Can anybody think of anything that fits my request?

Hmm thats very specific The Breaker has a very powerful protoganist although he's weak in the begining but becomes Incredibly powerful fast!

Until Death Do Us Part Has a blind swordsman with almost godlike abilities which he seems rather ablivious to!

Zetman maybe i love this series!

Beelzebub is somewhat like that?

Quote from ForteAtrox

Beelzebub is somewhat like that?

I second this, not because of the power but just cause it's so randomly hilarious.

Rurouni Kenshin

He's a legendary fighter (and I mean legendary - no one is better than him except maybe his master before he retired), but most people don't know this by looking at him. To most people he seems a little silly and fun and happy. But when it comes to protecting people, there's nothing he won't do.

Kanata Kara

Baccano! (Novel) - lots of these types in here.

Noblesse - lots in here too.

Trigun

For other series where the characters' "powers" aren't the typical "super strength" or "explosive energy" sorts:

Durarara!! (Novel) - the power of influence, like being the head of a gang. There are also some characters with supernatural powers.

Yakitate!! Japan - "solar hands" and prodigy talent, invaluable in the world of bread-making.