How old are your kids?
When our kids were little, we took the same opportunity to have a leisurely sit down dinner (we chose Marrakesh - one of our favorites), and stayed out to see Illuminations and actually take more than two seconds in the WS shops - they were too little to stay out that late and too antsy to shop.
Now they are older and can go to signature restaurants and stay up late enough for Illuminations, but still too little to really get a kick out of DisneyQuest (we haven't been yet, my six year old isn't quite ready), so dinner in DTD and DisneyQuest could be fun - but we didn't go kid-less this trip.
If you want to have an alcohol induced good time, the monorail drink-o-thon (start with dinner at CG, Narcoosees, Citricos, or even Artists Point and take the boat over to start the bar hap at CG) could be a lot of fun.
Being cheap, I think Cirque du Soliel is wonderful, but we just took our six and seven year old for the first time. If we'd had the opportunity when they were three and four, I think I'd have loved to go without them. Its an OK show for little kids, but a lot of money and they don't quite appreciate it yet. But its an amazing show for grown ups and older kids.
And, of course, Kungaloosh!