Which is correct?

Two popular songs during the gold rush were The Gold Digger’s Waltz and Oh, Susannah.

Two popular songs during the gold rush were “The Gold Digger’s Waltz” and “Oh, Susannah”.

Two popular songs during the gold rush were The Gold Digger’s Waltz and Oh, Susannah.

Two popular songs during the gold rush were “The Gold Digger’s Waltz” and “Oh, Susannah.”