Our favorites for a quick adults only trip are:
AKL-J - animals, bar, food, pool all in one place.
BWV/BCV - either as walking/exercising around the lake is great, watching fireworks for two parks.
SSR - as previously mentioned DTD.
Have you though about some things to do while you are there with no parks planned?
Depending upon what you are into:
sports: golf, mini-golf, fishing, marathon, bowling, ESPN Club, WWS/ESPN Zone, etc
shopping: DS (DTD), area outlet malls, large scale malls
drinking: Jellyrolls, Raglan Road, monorail tour of resorts, walking tour of resorts in the Boardwalk area
movies: DS (DTD) 24 screen theater some with meals served by waiters
night clubbing: Jellyrolls, Atlantic Dance, Raglan Road, Citywalk
resort tours: monorail tour of resorts, Boardwalk around the lake tour of resorts, horse drawn tour of FWC, AKL/AKV
offsite: Gaylord Palms Resort, Citywalk, swamp tour
eating: Formal GF 5* Chef's Table @ V&As