During this holiday time, every Park is decked out in full finery so just walking around will be a treat.
You don't mention which parks you plan to go to, but I'd hit MGM with the Osbourne Lights and Fantazmic. MK with the parades and WISHES, and EPCOT with illuminations. There's a special narrative reading event held at the pavillion in America at EPCOt with celebrity readers. See if one of the times is during your stay and get a seat early.
Plan to hit the parks early and to stay late.
Since you don't have kids along, the sky is the limit for dining choices.
My suggestions are Mama Melrose for dinner and Sci Fi drive inn for lunch at MGM. Pecos Bills for a wonderful burger lunch at MK and then head out on the monorail to the Poly and have dinner at Ohanas, then monorail back to MK for WISHES. At EPCOT, Biergarten for an early lunch (it will take awhile to work it off) and then Le Cellier in Canada for a late dinner. Just walk out of Canada and find a spot at the rail for Illuminations -- it usually starts around 9pm.
Check allearsnet for specific menus and park and event hours.
Your 3 days will fly by--have a wonderful time
