Hi Lizzie,
It would just be the Dankos. Something that belongs to your family would be the Dankos' or the Dankos's.

Kelsey: It should be The Englishes, and here's a source: http://grammar.quickanddirtytips.com/grammar-greetings.aspx
Lynne: No s is needed, and it should be "present," so the way you have it written is right.

I think it's Fishes, whether on a sign or when people are talking about you. Definitely no apostrophe, if you're not talking about possession. To pluralize Fish, I'd just say Fishes. And if something belongs to you two, I gather from previous comments that it would be the Fishes', pronounced "fishez." I think I'd pronounce it "fishezez," but I think I'd be wrong.

I once read that in America, you use an apostrophe, but in England, it's just the s.