What shopping items should I cross off my list first?

Very last minute: ice. Have someone pick up a bag of ice on the way to your house.

The only item I get the day before and I consider that last minute is the turkey which is always fresh. Everything else I like to have well ahead of the event.

Anything that goes into the pantry I buy on my first shopping trip after planning/setting a date for an event. Most ingredients for December holiday baking are always purchased by no later than the Sunday after Thanksgiving. Ditto for candles and small bags and pretty paper plates/decorative cellophane for sending home goodie bags/plates. (I always make plenty of extra treats for guests to take home.) Certain produce is purchased further in advance than other (think winter squash, onions, garlic, most carrots, if fresh looking, etc.); other than that, I usually buy it in the order in which I'm going to use it . I.e., produce for a chutney, relish or side dish made in advance is purchased and prepared before that which is prepared on the day of the event. But I suppose all this is rather obvious. ;o)

I pick up paper goods such as cocktail napkins, disposable hand towels for the bathrooms, dried flowers if needed for decoration way in advance when they tend to be on sale at craft stores. Produce I shop for produce two or three days in advance so I avoid the last-minute-ers; too, that way, I'm not sorting through dregs, driving around to several different markets, or even changing a menu because something is sold out.

I use fresh organic turkeys or goose, and always arrange to pick them up the day before. That way, something large isn't taking up too much fridge space for longer than necessary.

I like to get my turkey when they're on sale. Once a season, my grocery always sells them for something like 8 cents a pound, and that's when we buy.

Aside from that, completely agree with SKK except that I pick up my veggies 2 days before...I find that they get way too picked over when I wait.

What is OK to save for the last minute?

Dry goods, spices, canned foods, frozen foods, dairy, eggs, alcohol, beverages. Day before the dinner I purchase fresh vegetables, fruits, breads and pick up the pre-ordered meat or bird.