Deciding which paint to use has gotten much easier now that acrylic latexes have pushed oil-based paints almost to extinction. The acrylics offer superior performance (they don't harden with age, the way oils do, so they move and breathe without blistering), they don't mildew as readily, and they emit fewer VOCs, so they comply with new air-quality regulations. They also work over both oil- and water-based primers.
Use spray paint to refinish your old bicycle or give any surface a new finish - glitter, mirror or just a new solid color. A fresh coat of concrete paint on a basement walls can make a huge difference. Protect your garage floors from dirt and stains with an epoxy paint. Don’t forget your bookshelves — douse them with some furniture paint to make them look new, again.