Blue and Orange: The joy of the bright sun and the bright sky. Biologically is the best combo because of how sunny days make us feel. Orange and blue.
Gold and Silver: I agree that gold and silver do look good together because they are both really shiny metals and they look so sparkly and gorgeous and they would make the best jewellery.
Red and Blue: Definitely my favorite. A light blue with a bright but low key (oxymoronic) red is awesome to look at.
Silver and Black: Depending on how you put them, they can look very regal or fun and bright. This is definitely my favourite colour combination.