I voted for poly because the monorail, the resort is beautiful, the food is good, and it overall is one of my favorite places. However if you're not going to be in your room I do agree with an earlier post about not spending the extra money. The value resorts have great food courts with more choices than the other food court areas but value resort does not have table service as the other resorts do. I have stayed at all four choices you have given and here's my take on them:
Poly: first choice if you can afford it, it's very expensive. monorail service is the best. You can take a stroller or wheel chair right on it, unlike the bus service where you have to fold it up. Very clean, remember you do get what you pay for. There is a huge waterfall in the lobby and they give you leis when you check in. Also has kid area in lobby to make crafts. When we stayed there, there was bunny's on the back patio so while we were enjoying the room for our afternoon relax time, we watched the bunnys and people walk by.
Contemporary:although it is expensive too, it's a little cheaper than poly. Also has monorail service. Both places you can view MK fireworks. I picked poly over this resort due to the resort grounds are just prettier to look at. What makes this resort exciting is if you pay the extra $$ and get a room in the main building.
CBR: My personal favorite places to stay are moderate because they're good quality hotels and not as expensive as deluxe. My favorite moderate is Port Orleans, french quarter. it's quiet and has beautiful grounds as well. In this resort the rooms have all been redone so you'll get updated rooms (where even the poly and contem haven't been updated as recent as these rooms)
ASM: I'm actually staying in AS Movies next week. Like i said they have good food courts, the buses are a pain though, and when you stay here these resorts all share buses so they're crowded. The rooms are smaller, as well as the beds are full size and not queen like the deluxe. I've read alot of complaints of the rooms not being clean, but I have never had a dirty room at disney, ever. If you are picky and used to have finer things in life you might not want to stay here. The one thing about the value resorts is the big giant figures all over the place, the children love this. It's very festive.
I have no complaints about any of these resorts and January is perfect weather so enjoy your trip!