Barrels. I love barrels. They're so versatile and easy to use. You can do a lot of things with barrels: Touch It, go sideways in front/behind/over them, jump, use them a a Yo-Yo game, squeeze between them, and use them for riding practice. Barrels are so nice.
Also, I like the jumps that I made. They're made entirely from scrap lumber and landscaping poles, lightweight, tough, and painted with funky colors and patterns. I currently have a cow (Holstein) oxer complete with panels that say "Moo!", a bright purple vertical, and a florescent yellow vertical with fake flowers sticking out of the poles. Hopefully this spring I'll be able to make a candy-cane oxer and a party-cloud-sky vertical. I'll try to get some pictures.