Marry is easy: Boardwalk.
Date is tough - and kill even harder. Theme-wise, I'd probably kill Riviera - it's the most generic hotel-looking. But boy does it have some great food and bar options. Beach Club is pretty and themed and close to Epcot, but doesn't add much food-wise for me and with Boardwalk right there almost as close to Epcot, with more theming, Beach becomes a bit superfluous.
So I guess I'd have to date Riviera, and kill Beach. But I'd be very conflicted and guilty about it!