Would they respond to a family discussion about your desire for a special Christmas? My first thought was to find out what they would like to do, but since you've asked without any results, I think it's probably up to you to get the ball rolling.
Start a general discussion about past holidays. If there is some family activity they are nostalgic about, I'd try to re-visit it. Maybe it's something like going to a tree farm and cutting down the Christmas tree.
I'd also try to set out a couple of requests:
1. Everyone has to make a special hand-made Christmas present for 1 person (and they can't all pick Mom!) - maybe everyone picks a name out of a hat. If you want to suggest that all Christmas presents be handmade, that's okay too, but it might be a little tough for some non-creative people. Handmade doesn't have to be built or baked or sewn. If they have some musical or writing talent and want to write a song or a poem or short story, great. A compilation CD or a scrapbook or photo album is a good idea too. It will take the emphasis away from the store-bought gifts, and help nurture some Christmas spirit.
2. Plan a pot-luck family and friends one-day sports tournament for your boys over the holiday. Something like flag football or basketball or road hockey.
I also might take the pressure off having an "extra special" Christmas. I understand the motivation, but no matter what you do or don't do, this is going to be an extra special Christmas, because you are all going to be together. It will always be memorable, even if there aren't Hollywood-movie-type events planned. Cherish your time together and enjoy whatever celebrations happen as they happen.