What are some great Thanksgiving sides that can be served at room temperature?

http://www.seriouseats.com/recipes/2014/04/french-lentil-salad-with-goat-cheese-and-walnuts-from-my-paris-kitchen.html

I made that the other day except I swapped the goat cheese for feta (cow's milk) and used mustard powder (no dijon), rice wine vinegar and added a bit of sugar to the dressing. Also only had red and white onions, but added some green onion as well. Toast the walnuts but careful not to burn them. Maybe make it ahead and serve feta or goat cheese once you get there?

Quick-pickled vegetables, olives, shaved brussel sprout salads in viniagrette

A vegetable tart/crostata/pie of any sort is a great option. I'm a fan of the following French onion tart:
http://smittenkitchen.com/blog/2013/03/french-onion-tart-uk-cookbook-release/

This is a fantastic side that I've made multiple times: http://www.epicurious.com/recipes/food/views/Roasted-Vegetables-with-Pecan-Gremolata-236485
The onion salad Marian posted recently is shockingly good, too: https://food52.com/recipes/31997-roasted-onion-salad-with-arugula-and-walnut-salsa
Here's another roasted veg salad that is really tasty: http://www.sproutedkitchen.com/home/2013/11/14/autumn-salad-with-horseradish-vinaigrette-news.html
This salad is pretty surprising, and gorgeous to boot: https://food52.com/recipes/26899-molly-stevens-roasted-fennel-red-onion-and-orange-salad
One final idea: https://food52.com/recipes/28440-vera-obias-cheddar-black-pepper-cornbread

This was a huge hit at my last dinner party: http://www.epicurious.com/recipes/food/views/Roasted-Fennel-with-Olives-and-Garlic-240418

A corn casserole is very popular...and simple.

Also the NPR cranberry sauce is great...but not a sub for normal cranberry sauce as some people don't like the color and the horseradish element.
http://www.npr.org/templates/story/story.php?storyId=4176014

Cranberry sauce, of course, come to mind; the squash wedges everyone else mentioned sound great too. How about a nice salad, like the classic fruit/nuts/cheese/greens combo with a light vinaigrette? I'm trying to think of something you could make in a crockpot, which could be kept plugged in and out of the way somewhere, but I'm drawing a blank at the moment.

I usually do a roasted veg - like the squash wedges - as they are always nice at room temp. One of my favs is Brussel Sprouts with Balsamic and Pancetta from Barefoot Contessa. I've also been wanting to make this roasted veg salad by Giada. Looks like it wld be nice for Thanksgiving http://www.oprah.com/food/Roasted-Root-Vegetable-Salad-Recipe-Giada-de-Laurentiis-Recipes

Melissav's Caramelized Squash Wedges with Sage and Hazelnut Pesto is great for Thanksgiving and works really well at room temperature. I have brought it to parties and it is always a hit. https://food52.com/recipes/7374-caramelized-butternut-squash-wedges-with-a-sage-hazelnut-pesto

I haven't made it yet, but the Roasted Onion Salad from Plenty More also looks fabulous: https://food52.com/recipes/31997-roasted-onion-salad-with-arugula-and-walnut-salsa

This salad is one of my all-time favorites: https://food52.com/recipes/15584-northern-spy-s-kale-salad It can be made well in advance (even the day before) and served at room temperature.