MY BLENDER!!! (Actually, I have three: a regular blender, a smoothie/protein shake-sized blender, and an immersion blender.) They're great for smoothies, soups, sauces, or dressings. My favorite is the immersion blender, because you can use it right in the glass, or in the pan on the stove.
Last week I wasn't sure what to do with some of my veggies, so I made a soup. All I did was blend the peppers, tomatoes, and onions. Then I added some spices and browned ground-beef, and heated it on the stove. Instant soup! (Depending on what you add to the tomatoes (main ingredient), you can make a spaghetti sauce as well.)