This colorful, bright, delicious Persimmon Pomegranate Salad is a lovely addition to a Christmas feast. If those flavors aren't quite what you're looking for, I can also wholeheartedly recommend this Brussels Sprouts Salad with almonds and mint, which sounds a bit odd but tastes absolutely fabulous. For something a bit more traditional, a Pear Fennel Walnut Salad might do, or perhaps this Radicchio Arugula Date Salad.
You can always make a simple tossed green salad, or use these tips for coming up with your own creation with this How to Make a Winter Salad. Want to make it strictly Christmas-y? Try one of these Red and Green Salads.