I've been playing around with the newest expansion pack for The Sims 3... Seasons! So far my favorite season is winter - your Sim can add Christmas lights to their house, make snow angels and snowmen, build igloos, and even ice skate on the rivers and ponds!
This expansion adds all the seasons and has a town festival for each one, which is really cute. I didn't get any pics of that, but here are some cute ones of winter!