Diwali is my favorite festivals of all ( well its fav for most of the Indians but then I will speak for myself :)).. anyways, I love this festival because its a wonderful combination of both bright colors and lots and lots of lights. Its the most auspicious time to make the major purchases of the year like jewelry or car. The shopping list during Diwali includes new clothes, utensils, electronics, home linen, home decor etc etc etc.
I absolutely love doing the diwali puja followed by bursting crackers. But the high point for me is to decorate the entire house from inside to outside with lights, lamps, flowers and rangoli.